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WORKSHOP MANUAL ZERO TURN MOWER ZD18 ( F ) ,ZD21 ( F ), ZD25F,ZD28 ( F ) KiSC issued 04, 2009 A...
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This Workshop Manual has been prepared to provide servicing personnel with information on the mechanism, service and maintenance of ZD18(F), ZD21(F) and ZD28(F) KUBOTA ZD Series ZERO-TURN MOWER. It is divided into two parts, “Mechanism” and “Servicing” for each section.
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SAFETY INSTRUCTIONS ZD18(F) · ZD21(F) · ZD28(F), WSM SAFETY INSTRUCTIONS SAFETY FIRST This symbol, the industry’s “Safety Alert Symbol”, is used throughout this manual and on labels on the machine itself to warn of the possibility of personal injury. Read these instructions carefully.
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SAFETY INSTRUCTIONS ZD18(F) · ZD21(F) · ZD28(F), WSM SAFETY STARTING • Do not start the engine by shorting across starter terminals or bypassing the safety start switch. • Do not alter or remove any part of machine safety system. • Before starting the engine, make sure that all shift levers are in neutral positions or in disengaged positions.
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SAFETY INSTRUCTIONS ZD18(F) · ZD21(F) · ZD28(F), WSM VENTILATE WORK AREA • If the engine must be running to do some work, make sure the area is well ventilated. Never run the engine in a closed area. The exhaust gas contains poisonous carbon monoxide.
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SAFETY INSTRUCTIONS ZD18(F) · ZD21(F) · ZD28(F), WSM SAFETY DECALS · The following safety decals are installed on the machine. If a decal becomes damaged, illegible or is not on the machine, replace it. The decal part number is listed in the parts list.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 1. IDENTIFICATION When contacting your local KUBOTA distributor, always specify engine serial number (3), machine serial number (2), mower serial number (4) and hour meter reading. (1) Machine Identification Plate (4) Mower Serial Number...
Screws, bolts and nuts should be installed in their original position to prevent reassembly errors. • When special tools are required, use KUBOTA genuine special tools. Special tools which are not frequently used should be made according to the drawings provided.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 3. HANDLING PRECAUTIONS FOR ELECTRICAL PARTS AND WIRING To ensure safety and prevent damage to the machine and surrounding equipment, heed the following precautions in handling electrical parts and wiring. IMPORTANT • Check...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM • Securely clamp, being careful not to damage wiring. (1) Clamp (3) Clamp • Wind Clamp Spirally (4) Welding Dent (2) Wire Harness W1011458 • Clamp wiring so that there is no twist, unnecessary sag, or excessive tension, except for movable part, where sag be required.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [2] BATTERY • Take care not to confuse positive and negative terminal posts. • When removing battery cables, disconnect negative cable first. When installing battery cables, check for polarity and connect positive cable first.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM • Use sandpaper to remove rust from terminals. • Repair deformed terminal. Make certain there is no terminal being exposed or displaced. (1) Exposed Terminal (3) Sandpaper (2) Bend Terminal (4) Rust W1012346 •...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 4. LUBRICANTS, FUEL AND COOLANT Capacity Place Lubricants, fuel and coolant ZD18(F) ZD21(F) ZD28(F) 30 L No. 2-D diesel fuel Fuel 7.9 U.S.gals. No. 1-D diesel fuel if temperature 6.6 Imp.gals. is below – 10 °C (14 °F) 2.6 L...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Greasing, oiling (Machine) Place No. of greasing point Capacity Type of grease Motion control lever boss Motion control lever Center pin King pin SAE multi-purpose Until grease overflows type grease Front wheel...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 5. TIGHTENING TORQUES [1] GENERAL USE SCREWS, BOLTS AND NUTS Screws, bolts, and nuts whose tightening torques are not specified in this Workshop Manual should be tightened according to the table below.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [3] AMERICAN STANDARD SCREWS, BOLTS AND NUTS WITH UNC OR UNF THREADS Grade SAE GR.5 SAE GR.8 Unit N·m kgf·m ft-lbs N·m kgf·m ft-lbs Nominal Diameter 5/16 23.1 to 27.8 2.35 to 2.84 17.0 to 20.5...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 6. MAINTENANCE CHECK LIST After Service interval Period purchase Impor- Reference tant page Items year years Engine oil Change G-16 Engine oil filter Replace G-17 Transmission fluid Change G-19 Transmission oil filter...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 7. CHECK AND MAINTENANCE CAUTION • Be sure to check and service the machine on a flat place with engine shut off, the parking brake on and chock the wheels. [1] DAILY CHECK To prevent trouble from occurring, it is important to know the condition of the machine.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Tire Pressure WARNING To avoid personal injury: • Do not attempt to mount a tire on a rim. This should be done by a qualified person with the proper equipment. • Always maintain the correct tire pressure.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Coolant Level CAUTION To avoid personal injury: • Do not remove the radiator cap when the engine is hot. Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking and Cleaning Radiator to Prevent Overheating CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before cleaning. Daily or after every 5 hours of operation, check to be sure the radiator screen and radiator core are clean.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [2] CHECK POINTS OF INITIAL 50 HOURS Changing Engine Oil CAUTION • Be sure to stop the engine before changing oil. 1. Start and warm up the engine for approx. 5 minutes.
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IMPORTANT • To prevent serious damage to hydraulic system, the replacement filter must be a highly efficient, 10 μm filter. Use only a genuine KUBOTA filter or its equivalent. (1) Transmission Oil Filter Cartridge (2) Screw W1031068...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [3] CHECK POINT OF INITIAL 100 HOURS Adjusting Front Axle Pivot 1. Lift up and securely block the front of the machine. 2. Measure the clearance (A) between the front axle (3) and front axle support (2).
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [4] CHECKING POINTS OF INITIAL 200 HOURS Changing Transmission Fluid CAUTION • Be sure to stop the engine before changing the transmission fluid. 1. Place an oil pan underneath the transmission case.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Changing Rear Axle Case Oil (RH & LH) CAUTION • Be sure to stop the engine before changing the transmission fluid. 1. Place an oil pan underneath the rear axle gear case.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [5] CHECK POINTS OF EVERY 50 HOURS Checking Safety Device CAUTION To avoid personal injury: • Do not allow anyone near the machine while testing. • If the machine does not pass one of the following tests, do not operate the machine.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Test 6 (OPERATOR ON THE SEAT) 1. Start the engine. 2. Do not set the parking brake. 3. Shift the PTO lever (4) to “DISENGAGE” (OFF) position. 4. Grasp the motion control levers (3) and move then inward from “NEUTRAL LOCK”...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Greasing 1. Apply a grease to the following position as figures. CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before greasing. (1) King Pin (LH · RH) (5) Motion Control Levers (LH ·...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Greasing (Continued) 1. Apply a grease to the following position as figures. CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before greasing. (1) Machine Universal Joint...
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Cleaning Air Cleaner Element 1. The air cleaner uses a dry element, never apply oil. 2. Do not touch the filter element except where cleaning is required. To clean the element, use clean and dry compressed air on the inside of the element.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Battery Charging DANGER To avoid serious injury or death: • When the battery is being activated, hydrogen and oxygen gases in the battery are extremely explosive. Keep open sparks and flames away from the battery at all times, especially when charging the battery.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Fuel Lines And Fuel Filter CAUTION • Be sure to stop the engine and remove the key when attempting to make the following checks and changes. • Never fail to check the fuel lines periodically. The fuel lines are subject to wear and age.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Parking Brake CAUTION To avoid personal injury: • Stop the engine and chock the wheels before checking or adjusting. • Park the machine on a hard and level surface. IMPORTANT • Wrong adjustment may cause machine damage.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Adjustment of brake spring play 1. Place the motion control lever to “NEUTRAL LOCK” position. 2. Be sure to chock the rear wheels. 3. Release the parking brake. 4. Loosen the lock nuts.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [7] CHECK POINTS OF EVERY 150 HOURS Changing Mower Gear Box Oil 1. See page G-25. W1036280 [8] CHECK POINTS OF EVERY 200 HOURS Adjusting Front Axle Pivot 1. See page G-18.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Adjusting the Motion Control Lever Pivot CAUTION To avoid personal injury: • Be sure to stop the engine and set the parking brake to “ON” before checking. 2 to 15 mm Lever free travel (A) Factory spec.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [9] CHECK POINTS OF EVERY 400 HOURS Replacing Fuel Filter 1. Disconnect the fuel hoses and loosen the filter band to replace the fuel filter (2). NOTE • If the fuel line is removed, be sure to properly bleed the fuel system.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Flushing Cooling System and Changing Coolant CAUTION • Do not remove the radiator cap when the engine is hot. Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Flushing Cooling System and Changing Coolant (Continued) Anti-Freeze If coolant freezes, the cylinders and radiator can be damaged. It is necessary, if the ambient temperature falls below 0 °C (32 °F), to remove coolant mix it with anti-freeze and full the radiator with 1.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [11] CHECK POINT OF EVERY 2 YEARS Replacing Hydraulic Hose 1. Replace the hose. Refer to “Checking Hydraulic Hose”. (See page G-30.) W1067327 Replacing Radiator Hose 1. Replace the hoses and clamps.
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [12] OTHERS Replacing Fuses 1. The electrical system is protected from potential damage by fuses. A blown fuse indicates that there is an overload or short somewhere in the electrical system. 2. If any of the fuses should blow, replace with a new one of the same capacity.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Mower Blade and Replacing Mower Blade 1. Check the cutting edge of mower blade. 2. Sharpen the cutting edges, if the mower blades are as shown in figure (2). 3. Replace the mower blades, if they are as shown in figure (3).
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM 8. SPECIAL TOOLS [1] SPECIAL TOOLS FOR ENGINE Special Use Puller Set Code No: 07916-09032 Application: Use exclusively for pushing out bearing, gears and other parts with ease. W1048293 Piston Ring Compressor...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Nozzle Tester Code No: 07909-31361 Application: Use to check the fuel injection pressure and spray pattern of nozzle. Measuring: 0 to 50 MPa range (0 to 500 kgf/cm , 0 to 7000 psi)
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Injection Pump Pressure Tester Application: Use to check fuel tightness of injection pumps. Pressure gauge full scale: More than 29.4 MPa (300 kgf/cm , 4267 psi) Copper gasket Flange (Material: Steel) Hex. nut 27 mm (1.06 in.) across the plat...
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Bushing Replacing Tool Application: Use to press out and to press fit the bushing. 1. For small end bushing 145 mm (5.71 in.) 20 mm (0.79 in.) 100 mm (3.94 in.) 19.90 to 19.95 mm dia. (0.7835 to 0.7854 in. dia.) 21.90 to 21.95 mm dia.
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G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM Crankshaft Bearing 1 Replacing Tool Application: Use to press out and to press fit the crankshaft bearing [Press Out] 135 mm (5.31 in.) 72 mm (2.83 in.) 1.57 rad. (40°) 10 mm (0.39 in.) 22 mm (0.87 in.)
G GENERAL ZD18(F) · ZD21(F) · ZD28(F), WSM [2] SPECIAL TOOLS FOR MACHINE Relief Valve Pressure Tester Code No: 07916-50045 Application: This allows easy measurement of relief set pressure. (1) Gauge (07916-50322) (6) Adaptor C (PS3/8) (07916-50371) (2) Cable (07916-50331)
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM 1. TROUBLESHOOTING Reference Symptom Probable Cause Solution Page Engine Does Not • No fuel Replenish fuel – Start • Air in the fuel system Bleed fuel system – • Water in the fuel system Change fuel and –...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Reference Symptom Probable Cause Solution Page Engine Revolution Is • Fuel filter clogged or dirty Replace fuel filter G-32 Not Smooth • Air cleaner clogged Clean or replace air G-25 cleaner element. • Fuel leak due to loose injection pipe retaining...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Reference Symptom Probable Cause Solution Page Fuel Mixed into • Injection pump’s plunger worn Replace pump 1-S31, S35 Lubricant Oil element or injection pump • Deficient nozzle injection Repair or replace 1-S28, S75 nozzle •...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Reference Symptom Probable Cause Solution Page Engine Overheated • Engine oil insufficient Replenish engine oil G-16 • Fan belt broken or tensioned improperly Replace fan belt or G-27, adjust fan belt 1-S46 tension •...
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM 2. SERVICING SPECIFICATIONS [D722-E-XFM5, D782-E-XFM5] [1] ENGINE BODY Item Factory Specification Allowable Limit Cylinder Head Surface Flatness – 0.05 mm 0.0020 in. Top Clearance 0.50 to 0.70 mm – 0.0197 to 0.0276 in.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Valve Spring Free Length 31.3 to 31.8 mm 28.4 mm 1.232 to 1.252 in. 1.118 in. Setting Load 64.7 N 54.9 N 6.6 kgf 5.6 kgf 14.6 lbs...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Timing Gear Crank Gear to Idle Gear Backlash 0.043 to 0.124 mm 0.15 mm 0.00169 to 0.00488 in. 0.0059 in. Idle Gear to Cam Gear Backlash 0.047 to 0.123 mm...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Crankshaft Alignment – 0.02 mm 0.0008 in. Crankshaft Journal to Crankshaft Bearing Oil Clearance 0.034 to 0.106 mm 0.20 mm 0.00134 to 0.00417 in. 0.0079 in.
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM 3. SERVICING SPECIFICATIONS [D1105-E-ZD] [1] ENGINE BODY Item Factory Specification Allowable Limit Cylinder Head Surface Flatness – 0.05 mm 0.0020 in. Top Clearance 0.55 to 0.70 mm – 0.0217 to 0.0276 in. Compression Pressure (When Cranking with Starting Motor) 2.84 to 3.24 MPa...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Valve Spring Free Length 37.0 to 37.5 mm 36.5 mm 1.457 to 1.476 in. 1.437 in. Setting Load 117.6 N 100.0 N 12.0 kgf 10.2 kgf 26.4 lbs...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Timing Gear Crank Gear to Idle Gear Backlash 0.032 to 0.115 mm 0.15 mm 0.0013 to 0.0045 in. 0.0059 in. Idle Gear to Cam Gear Backlash 0.036 to 0.114 mm...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Crankshaft Journal to Crankshaft Bearing Oil Clearance 0.034 to 0.114 mm 0.20 mm 0.00134 to 0.00449 in. 0.0079 in. Crankshaft Journal O.D. 47.934 to 47.950 mm –...
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM 4. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts : See page G-9.) Item Size × Pitch N·m kgf·m...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [D1105-E-ZD] Item Size × Pitch N·m kgf·m ft-lbs M10 × 1.25 Air cleaner stay nut 48.1 to 55.9 4.9 to 5.7 35.4 to 41.2 M6 × 1.0 * Bearing case cover screw 9.8 to 11.3 1.00 to 1.15...
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM 5. CHECKING, DISASSEMBLING AND SERVICING [1] SEPARATING ENGINE (1) Disassembling and Assembling Draining Engine Oil 1. Park the machine on level ground. 2. Start and warm up the engine for approx. 5 minutes.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Draining Coolant CAUTION • Never open the radiator cap while operating or immediately after stopping. Otherwise, hot water will spout out from the radiator. Wait for more than ten minutes to cool the radiator, before opening the cap.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [ZD18(F) · ZD21(F)] Battery CAUTION • When disconnecting the battery cables, disconnect the negative cable from the battery first. When connecting, connect the positive cable to the battery first. 1. Remove the battery cover (1).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Engine Disassembly 1. Remove the universal joint mounting screws (1). 2. Disconnect the universal joint (2) from fun drive pulley. 3. Pull out the snap pins from the radiator. 4. Remove the engine mounting nuts.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [ZD28(F)] Battery and Bonnet CAUTION • When disconnecting the battery cables, disconnect the negative cable from the battery first. When connecting, connect the positive cable to the battery first. 1. Remove the battery cover (1).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Dynamo, Fan Belt and Muffler 1. Disconnect the radiator hoses and separate the radiator (1) with recovery tank (5) from engine assembly. 2. Remove the cooling fan (2) and fan pulley. 3. Remove the dynamo (6) and fan belt (7).
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [2] ENGINE BODY (1) Checking and Adjusting Compression Pressure 1. Run the engine until it is warmed up. 2. Stop the engine. 3. Disconnect the 2P connector from the fuel pump. 4. Remove the air cleaner, the muffler and all injection nozzles.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Top Clearance 1. Remove the cylinder head. (Do not attempt to remove the cylinder head gasket.) 2. Move the piston up, and stick a strip of fuse [1.5 mm dia. (0.059 in. dia.), 5 to 7 mm long (0.197 to 0.276 in. long)] on the piston head at three positions with grease so as to avoid the intake and exhaust valves and the combustion chamber ports.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Valve Clearance IMPORTANT • The valve clearance must be checked and adjusted when engine is cold. 1. Remove the cylinder head cover and the glow plugs. 2. Align the “1TC” mark (1) on the flywheel and alignment mark (2) on the rear end plate so that the No.
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (2) Disassembling and Assembling (A) Cylinder Head and Valves Cylinder Head Cover 1. Remove the head cover cap nuts. 2. Remove the cylinder head cover. (When reassembling) • Check to see if the cylinder head cover gasket is not defective.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Removal Procedure for Nozzle Heat Seal Service IMPORTANT • Use a plus (phillips head) screw driver (1) that has a Dia. bigger than the heat seal hole (Approx. 6 mm) 1/4 in.. 1. Drive a screw driver (1) lightly into the heat seal hole.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Cylinder Head 1. Loosen the pipe clamp, and remove the water return pipe. 2. Remove the cylinder head bolt in the order of (14) to (1). 3. Lift up the cylinder head to detach.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Timing Gears, Fuel Camshaft and Camshaft [D722-E-XFM5, D782-E-XFM5] Injection Pump and Speed Control Plate 1. Remove the socket head screws and nuts, and remove the injection pump (3). 2. Remove the screws and separate the speed control plate (2), taking care not to damage the spring (4).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Gear Case 1. Remove the screw (1). 2. Disconnect the start spring (2) in the speed control plate mounting hole. 3. Remove the gear case (3). (When reassembling) • Apply a liquid gasket (Three Bond 1215 or equivalent) to both sides of the gear case gasket (4).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Fuel Camshaft 1. Remove the screws and draw out the camshaft with the gear on 2. Remove the retaining plate (1). 3. Remove the screws, then draw out the injection pump gear (2) and fuel camshaft (3) with the governor fork assembly.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Water Pump 1. Remove the water pump flange. (When reassembling) • Before installing the water pump flange gasket, apply liquid gasket (Three Bond 1215 or equivalent) to the both side. W1035410 Gear Case 1.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Injection Pump 1. Remove the injection pump mounting screws and nuts. 2. Align the control rack pin (2) with the notch (3) on the crankcase, then remove the injection pump (1). 3. Remove the injection pump timing shims.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Governor Shaft 1. Remove the pump cover. 2. Remove the external snap ring (1) from the governor shaft (2). 3. Pull out the governor shaft (2). (When reassembling) • Make sure assembling the external snap ring of the governor shaft.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Fork Lever 1. Remove the start spring (7). 2. Remove the fork lever shaft cover (1). 3. Pull out the fork lever shaft (4), and remove the spacer (2), bearing (3), fork levers 1 (6) and 2 (5).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (D) Connecting Rod and Piston Oil Pan and Oil Strainer 1. Remove the oil pan (4). 2. Remove the oil strainer (3). (When reassembling) • Install the oil strainer, using care not to damage the O-ring (1).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Piston 1. Turn the flywheel and bring the No. 1 piston to the top dead center. 2. Pull out the piston upward by lightly tapping it from the bottom of the crankcase with the grip of a hammer.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Piston Ring and Connecting Rod 1. Remove the piston rings using a piston ring tool. 2. Remove the piston pin (1), and separate the connecting rod (7) from the piston (2). (When reassembling) •...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (E) Crankshaft Flywheel 1. Lock the flywheel not to turn using flywheel stopper. 2. Remove the flywheel screws, except for two which must be loosened and left as they are. 3. Set a flywheel puller (Code No: 07916-32011), and remove the flywheel.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Crankshaft 1. Remove the main bearing case screw 2 (1). (D722 · D1105) 2. Pull out the crankshaft assembly. (D782) 3. Turn the crankshaft to set the crank pin of the third cylinder to the bottom dead center.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Main Bearing Case Assembly 1. Remove the two bearing case screws 1 (4), and remove the main bearing case assembly (3), being careful with the thrust bearing (2) and crankshaft bearing 2. 2. Remove the main bearing case assemblies 1 (5), 2 (1).
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (3) Servicing (A) Cylinder Head and Valve Cylinder Head Surface Flatness 1. Clean the cylinder head surface. 2. Place a straightedge on the cylinder head’s four sides and two diagonal as shown in the figure.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Valve Recessing 1. Clean the cylinder head surface, valve face and valve seat. 2. Insert the valve into the valve guide. 3. Measure the valve recessing with a depth gauge. 4. If the measurement exceeds the allowable limit, replace the valve.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Replacing Valve Guide (When removing) 1. Press out the used valve guide using a valve guide replacing tool. (When installing) 1. Clean a new valve guide and valve guide bore, and apply engine oil to them.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Correcting Valve and Valve Seat NOTE • Before correcting the valve and seat, check the valve stem and the I.D. of the valve guide section, and repair them if necessary. • After correcting the valve seat, be sure to check the valve recessing.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Free Length and Tilt of Valve Spring 1. Measure the free length (A) of valve spring with venire calipers. If the measurement is less than the allowable limit, replace it. 2. Put the valve spring on a surface plate, place a square on the side of the valve spring.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Rocker Arm and Rocker Arm Shaft 1. Measure the rocker arm shaft O.D. with an outside micrometer. 2. Measure the rocker arm I.D. with an inside micrometer, and then calculate the oil clearance.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Tappet and Tappet Guide Bore 1. Measure the tappet O.D. with an outside micrometer. 2. Measure the I.D. of the tappet guide bore with a cylinder gauge, and calculate the oil clearance.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Timing Gears, Camshaft and Fuel Camshaft Timing Gear Backlash 1. Set a dial indicator (lever type) with its tip on the gear tooth. 2. Move the gear to measure the backlash, holding its mating gear.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Idle Gear Side Clearance 1. Set a dial indicator with its tip on the idle gear. 2. Measure the side clearance by moving the idle gear to the front and rear. 3. If the measurement exceeds the allowable limit, replace the idle gear collar.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Cam Height 1. Measure the height of the cam at its highest point with an outside micrometer. 2. If the measurement is less than the allowable limit, replace the camshaft. [D722 · D782] 26.88 mm...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Idle Gear Shaft and Idle Gear Bushing 1. Measure the idle gear shaft O.D. with an outside micrometer. 2. Measure the idle gear bushing I.D. with an inside micrometer, and calculate the oil clearance.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (C) Piston and Connecting Rod Piston Pin Bore I.D. 1. Measure the piston pin bore I.D. in both the horizontal and vertical directions with a cylinder gauge. 2. If the measurement exceeds the allowable limit, replace the piston.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Replacing Small End Bushing (When removing) 1. Press out the used bushing using a small end bushing replacing tool. (When installing) 1. Clean a new small end bushing and bore, and apply engine oil to them.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Clearance between Piston Ring and Piston Ring Groove 1. Clean the rings and the ring grooves, and install each ring in its groove. 2. Measure the clearance between the ring and the groove with a feeler gauge.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Crankshaft Side Clearance 1. Set a dial indicator with its tip on the end of the crankshaft. 2. Measure the side clearance by moving the crankshaft to the front and rear. 3. If the measurement exceeds the allowable limit, replace the main bearing case assembly.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Crankshaft Alignment 1. Support the crankshaft with V blocks on the surface plate at both end journals. 2. Set a dial indicator with its tip on the intermediate journal. 3. Measure the crankshaft alignment.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Crankpin and Crankpin Bearing (Continued) (Reference) • Undersize crankpin bearing [D722 · D782] Undersize Bearing Code Number Marking 0.2 mm Crankpin bearing 02 15861-22970 020 US 0.008 in. 0.4 mm...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1 1. Measure the O.D. of the crankshaft front journal with an outside micrometer. 2. Measure the I.D. of the crankshaft bearing 1 with an inside micrometer, and calculate the oil clearance.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1 (Continued) (Reference) • Undersize crankshaft bearing 1 [D722 · D782] Undersize Bearing Code Number Marking 0.2 mm Crankshaft bearing 1 02 15861-23910 020 US 0.008 in.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Replacing Crankshaft Bearing 1 (When removing) 1. Press out the used crankshaft bearing 1 using a crankshaft bearing 1 replacing tool. (When installing) 1. Clean a new crankshaft bearing 1 and crankshaft journal bore, and apply engine oil to them.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 and Crankshaft Bearing 3 1. Put a strip of plastigage (Code No. 07909-30241) on the center of the journal. 2. Install the bearing case and tighten the bearing case screws 1 to the specified torque, and remove the bearing case again.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 and Crankshaft Bearing 3 (Continued) (Reference) • Undersize crankshaft bearing 2 and 3 [D722 · D782] Undersize Bearing Code Number Marking Crankshaft bearing 2 02...
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Cylinder Wear 1. Measure the cylinder liner I.D. at the six positions (see figure) with a cylinder gauge to find the maximum and minimum I.D.’s. 2. Get the difference (Maximum wear) between the maximum and the minimum I.D.’s.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Correcting Cylinder 1. When the cylinder is worn beyond the allowable limit, bore and hone it to the specified dimension. [D722 · D782] 67.250 to 67.269 mm Factory spec. 2.64764 to 2.64839 in.
ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [3] LUBRICATING SYSTEM (1) Checking Engine Oil Pressure 1. Remove the engine oil pressure switch, and set a oil pressure tester (Code No. 07916-32032). (Adapter screw size : PT 1/8) 2. Start the engine. After warming up, measure the oil pressure of both idling and rated speeds.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Clearance between Rotor and Cover 1. Put a strip of plastigage (Code No. 07909-30241) onto the rotor face with grease. 2. Install the cover and tighten the screws. 3. Remove the cover carefully, and measure the amount of the flattening with the scale and get the clearance.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [4] COOLING SYSTEM (1) Checking and Adjusting (A) Fan Belt Fan Belt Tension 1. Measure the deflection (A), depressing the belt halfway between the fan drive pulley and alternator pulley at specified force (98 N, 10 kgf, 22 lbs).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Radiator CAUTION • When removing the radiator cap, wait at least ten minutes after the engine has stopped and cooled down. Otherwise, hot water may gush out, scalding nearby people. Radiator Water Leakage 1.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (2) Disassembling and Assembling Thermostat Assembly 1. Remove the thermostat cover mounting screws, and remove the thermostat cover (1). 2. Remove the thermostat assembly (3). (When reassembling) • Apply a liquid gasket (Three Bond 1215 or equivalent) only at the thermostat cover side of the gasket (2).
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM [5] FUEL SYSTEM (1) Checking and Adjusting (A) Injection Pump Injection Timing 1. Remove the bonnet and air cleaner. 2. Remove the muffler. 3. Remove the injection pipes and glow plugs. 4. Engage the parking brake.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM Fuel Tightness of Pump Element 1. Remove the bonnet and air cleaner. 2. Remove the muffler. 3. Disconnect the accelerator wire. 4. Remove the air cleaner stay. 5. Remove the injection pipes and glow plugs.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Injection Nozzle CAUTION • Check the injection pressure and condition after confirming that there is nobody standing in the direction the fume goes. If the fume from the nozzle directly contacts the human body, cells may be destroyed and blood poisoning may be caused.
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ENGINE ZD18(F) · ZD21(F) · ZD28(F), WSM (2) Disassembling and Assembling (A) Injection Nozzle Nozzle Holder 1. Secure the nozzle retaining nut (7) with a vise. 2. Remove the nozzle holder (1), and take out parts inside. (When reassembling) • Assemble the nozzle in clean fuel oil.
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM (2) Pump and Motor (1) Swashplate (4) Oil (7) Swashplate (A) Pump (2) Piston (5) Cylinder (B) Motor (3) Cylinder (6) Piston Pump and motor cylinder, each containing pistons, are connected by lines. Cylinders and lines are filled with oil.
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM (6) Power Trains Operation [Serial No. Affected: below 20000] (1) Hydraulic Pump (3) Regulator Valve (5) Lubricating Orifice (7) Pump (2) Oil Filter (4) Check Valve (6) Neutral Orifice (8) Motor Neutral With the control levers in the NEUTRAL position, the piston springs in the pump block in the pumps force the swash plates to a position that is parallel to the pump body.
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM (7) Control Linkage (1) Motion Control Lever (3) Trunnion Arm (5) Speed Shaft (6) Neutral Slot (2) Speed Control Rod (4) Speed Limit Spring The motion control lever (1) and the trunnion shaft of variable swashplate are linked with the speed shaft (5), speed control rod (2) and the trunnion arm (3).
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM (8) Final Reduction Gear Section As for this machine, power is transmitted from the 12T gear (1) on the HST motor shaft to the rear axle (5) through 53T gear, 14T gear shaft and 57T gear.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Regulator Valve This machine is controlled with the regulator valve so that the oil sent from the hydraulic pump may become the setting pressure. And the oil flows into PTO clutch and hydrostatic transmission.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Parking Brake (1) Parking Brake Lever (4) Parking Brake Spring (6) Parking Brake Rod (8) Brake Drum (2) Parking Brake Lock Pedal (5) Return Spring (7) Brake Assembly (9) Brake Shoe (3) Brake Plate The parking brake is composed of parking brake lever (1), parking brake lock pedal (2), brake plate (3), parking brake rod (6) and brake assembly (7).
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-8.) Item N·m kgf·m ft-lbs Motion control lever mounting bolt and nut 17.7 to 20.6...
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 4. CHECKING AND ADJUSTING Checking Neutral 1. Park machine safely. 2. Set the motion control levers are in the NEUTRAL position. 3. Move the PTO lever to OFF position and apply the parking brake.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Creep in Forward CAUTION To avoid personal injury: • Park the machine on a hard and level surface. • If it is necessary to run engine in an enclosed area, use a gas tight exhaust pipe extension to remove the fumes.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Adjusting Maximum Speed CAUTION To avoid personal injury: • Park the machine on a hard and level surface. • If it is necessary to run engine in an enclosed area, use a gas tight exhaust pipe extension to remove the fumes.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Motion Control Lever Alignment CAUTION • When checking, park the tractor on flat ground, apply the parking brake. 1. Check the gap (A) and space (B) between the motion control levers, at the maximum forward position.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Checking Hydrostatic Transmission [Serial No. Affected: above 20001] CAUTION • When checking, park the machine on flat ground, apply the parking brake. • Sit on operator’s seat for checking. 1. After worming up the machine, apply the parking brake and set the stop wood (chock) to the rear wheels.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM PTO Clutch Operating Pressure (Hydrostatic Transmission Charge Pressure) CAUTION • When checking, park the tractor on flat ground, apply the parking brake. 1. Remove the eye joint bolt (1), then install the adaptor cable and pressure gauge.
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 5. DISASSEMBLING AND ASSEMBLING [1] SEPARATING TRANSAXLE Draining Transmission Fluid CAUTION • Be sure to stop the engine before changing the transmission fluid. 1. Place an oil pan underneath the transmission case. 2. Remove the drain plugs (1) at the bottom of the transmission case and drain the oil completely.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Seat, ROPS, Motion Control Levers, Fenders and Others 1. Disconnect the seat safety switch. 2. Remove the seat open rod (13) and seat assembly with seat frame (5). 3. Remove the ROPS upper (1). (ROPS Models) 4.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Upper Frame 1. Disconnect the connectors from limit switches. 2. Disconnect the connectors from regulator (2) and combination box (3), then remove the wire harness (1) from upper frame. 3. Remove the PTO rod, lift rod and disconnect the throttle wire.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Universal Joint and Under Frame [ZD28(F)] 1. Remove the propeller shaft (1). 2. Remove the clamp for fuel hoses, wire harness and delivery hose (4). 3. Disconnect the delivery hose (4) from oil cooler (3).
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Hydraulic Pipes 1. Remove the delivery hose (4) and pipe as a unit. 2. Remove the hydraulic pipes. (When reassembling) • Take care not to damage the O-rings. NOTE • When installing the O-ring and coller (3), note the position of O-ring onto the delivery pipe shown in the figure.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Center Section 1. Remove the center section mounting hex. socket head screws. 2. Tap the center section (1) with soft hammer and separate the center section (1) from the HST housing (2). (When reassembling) •...
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Cylinder Block Assembly and Thrust Ball Bearing 1. Lay the housing on its side. 2. Slide out the cylinder bloke assembly (pump) (1). 3. Slide out the cylinder block assembly (motor) (3) with the motor shaft (2).
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Slot Guide and Cradle Bearing 1. Remove the slot guide (2) from the trunnion arm (3). 2. Remove the cradle bearing (1) from the housing. (1) Cradle Bearing (3) Trunnion Arm (2) Slot Guide...
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Disassembling PTO Clutch Assembly 1. Remove the bearing (1) and clutch gear (2). 2. Tap out the PTO clutch shaft (3) from clutch case (8). 3. Remove the internal snap ring (16), then remove the pressure plate (15), clutch disc and clutch plate (17).
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Regulator Valve 1. Remove the internal snap ring (5), plug (4), spring (3) and poppet (2). (When reassembling) • Take care not to damage the O-rings. (1) Center Cover Assembly (4) Plug (2) Poppet...
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Brake Shaft and Rear Axle 1. Remove the brake cover assembly (1). 2. Remove the external snap ring (3) and brake drum (4). 3. Remove the ball bearing (6). 4. Remove the 57T gear (7) and brake shaft (8).
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 6. SERVICING [1] HYDROSTATIC TRANSMISSION Center Section 1. Check the surface (1) of center section for scratches or wear. If deep scratch or excessive wear is found, replace the hydrostatic transmission assembly. (1) Surface...
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Thrust Washer, Thrust Ball Bearing and Thrust Plate 1. Check the thrust ball bearing (3) for scratches and excessive wear. 2. If worn, replace. 3. Check the thrust plate (4) for scratches and excessive wear.
TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM [2] TRANSMISSION CASE Checking Bearing 1. Hold the inner race, and push and pull the outer race in all directions to check for wear and roughness. 2. Apply transmission fluid to the bearing, and hold the inner race.
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TRANSAXLE ZD18(F) · ZD21(F) · ZD28(F), WSM Correcting of Tooth Contact 1. Proper contact. • No adjustment. W1028600 2. Correcting of the heel contact and shallow contact. • It is confirmed whether there is a shim (3). • The 16T or 18T bevel gear (5) can be moved to backward by doing to add the shim (3) when not is.
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FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 1. STRUCTURE (1) Cap (3) Taper Roller Bearing (5) Lift Up Adjuster (7) Slotted Nut (2) Taper Roller Bearing (4) Wheel Bracket (6) Front Axle (8) Center Pin The front axle is constructed as shown above. The shape of the front axle is relatively simple, and the front axle is supported at its center with the center pin (8), so that steering operation is stable even on uneven grounds in a grass field.
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SERVICING CONTENTS 1. TROUBLESHOOTING ..................3-S1 2. SERVICING SPECIFICATIONS ..............3-S2 3. TIGHTENING TORQUES ................3-S3 4. CHECKING, DISASSEMBLING AND SERVICING........3-S4 [1] CHECKING AND ADJUSTING ...............3-S4 [2] DISASSEMBLING AND ASSEMBLING..........3-S5 (1) Separating Front Wheel and Wheel Bracket........3-S5 KiSC issued 04, 2009 A...
FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 1. TROUBLESHOOTING Reference Symptom Probable Cause Solution Page Front Wheels • Clearance between center pin and front axle Replace – Wander to Right or excessive Left • Force of the lock nut which tighten the wheel...
FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 2. SERVICING SPECIFICATIONS Item Factory Specification Allowable Limit Front Axle End Play Clearance 0 to 0.2 mm 0.5 mm 0 to 0.008 in. 0.02 in. W1013874 3-S2 KiSC issued 04, 2009 A...
FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-8.) Item N·m kgf·m ft-lbs Wheel bolt and lock nut 20 to 25 2.04 to 2.55...
FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM 4. CHECKING, DISASSEMBLING AND SERVICING [1] CHECKING AND ADJUSTING Adjusting Front Axle Pivot 1. Lift up and securely block the front of the machine. 2. Measure the clearance (A) between the front axle (3) and front axle support (2).
FRONT AXLE ZD18(F) · ZD21(F) · ZD28(F), WSM [2] DISASSEMBLING AND ASSEMBLING (1) Separating Front Wheel and Wheel Bracket Remove the Front Wheel 1. Inspect all parts for wear or damage. Replace the parts as needed. (When reassembling) • Apply grease to grease fittings. (See page G-7.) 20 to 25 N·m...
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HYDRAULIC SYSTEM KiSC issued 04, 2009 A...
HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 2. HYDRAULIC PUMP The oil pump in this engine is a trochoid pump. Inside the pump body, the 6 lobe inner rotor (2) is eccentrically engaged with the 7 lobe outer rotor (1). The inner rotor is driven by the input shaft, which in turn rotate the outer rotor.
HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 3. HYDRAULIC CONTROL VALVE AND VALVE ADAPTOR (1) Return Pipe (3) Control Valve (5) Cylinder Hose A: From Hydraulic Pump (2) Delivery Pipe (4) Control Valve Adaptor (6) Lift Cylinder B: To Transmission Case The hydraulic system consists of the control valve (3), control valve adaptor (4), lift cylinder (6) and etc..
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HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Neutral (1) Valve Cover (5) Control Valve Adaptor (9) Relief Valve A: To Hydrostatic Transmission (2) Spool (6) Relief Cover (10) P (Pump) Port C: To Lift Cylinder (3) Valve Body (7) Control Lever...
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HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Overloaded (1) Spool (3) R (Return) Port (5) P (Pump) Port A: To Hydrostatic Transmission (2) Control Valve Adaptor (4) Relief Valve (6) C (Cylinder) Port If the pressure in the circuit exceeds the relief valve setting pressure (3.14 to 3.73 MPa, 32 to 38 kgf/cm , 455 to 540 psi), the relief valve (4) opens to release pressure-fed oil.
HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 4. LIFT CYLINDER (1) Tube End (2) Snap Ring (3) Cylinder Tube (4) Packing (5) Scraper (6) Piston Rod W1014031 The lift cylinder consists of the tube end (1), cylinder tube (3), piston rod (6) and other parts as shown in the figure above.
HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 3. CHECKING, DISASSEMBLING AND SERVICING [1] HYDRAULIC CONTROL VALVE, PUMP AND CYLINDER (1) Checking and Adjusting Relief Valve Setting Pressure 1. Remove the eye joint bolt (1) from the hydraulic. 2. Install the adaptor, cable and pressure gauge.
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HYDRAULIC SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Relief Cover and Relief Valve 1. Unscrew the relief cover mounting screws (6), and remove the relief cover (7). 2. Remove the spool return spring (9). 3. Unscrew the adjusting screw (1), and remove the adjusting shim (2), spring (3), poppet (4) and valve seat (5).
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 2. STARTING SYSTEM [ZD18(F) · ZD21(F)] When the main switch is turned to the PREHEAT position, the terminal 30 is connected to the terminals 19 and AC. The glow plugs become red-hot, and the preheat indicator lamp also lights on while preheating.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [ZD28(F)] When the main switch is turned to the PREHEAT position, the terminal 30 is connected to the terminals 19 and AC. The glow plugs become red-hot, and the preheat indicator lamp also lights on while preheating.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [2] Glow Plug This plug is a two-material type QGS (Quick Glow System) for quick temperature rise, and has self- controlling function as well as excellent durability. The heater (4) connected in series to the heater (3), which also functions as the resistor, is incorporated in the sheath tube (1) of the super glow plug.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [4] FUEL PUMP An electro magnetic fuel pump uses a transistor that causes the pump to start pumping fuel when the main switch is turned to the “ON” position. Therefore, fuel is supplied to the fuel injection pump regardless of engine speed.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 3. CHARGING SYSTEM The charging system supplies electric power for various electrical devices and also charges the battery while the engine runs. It consists of a AC dynamo and a regulator. 5-M10...
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [1] AC DYNAMO The dynamo is an 8-8 pole rotating magnet type generator. It is simple in construction, consisting of a stator and rotor. The rotor is made up of eight permanent...
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [3] EASY CHECKER To check the conditions of tractor easily before and during operation, easy checker combination of lamps on the easy checker board is provided. Indication Items (1) Oil Pressure Lamp When the engine oil pressure is low, this lamp illuminates.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 4. GAUGES The fuel quantity and coolant temperature are indicated by the ammeters. The ammeters indicate each amperage flowing through the fuel level sensor for the fuel quantity detection and through the coolant temperature sensor for the coolant temperature detection.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [2] COOLANT TEMPERATURE Coolant Temperature Sensor The coolant temperature sensor is installed to the cylinder head of engine, and its tip is in touch with the coolant. It contains a thermistor (4) whose electrical resistance decreases as the temperature increases.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 1. TROUBLESHOOTING Reference Symptom Probable Cause Solution Page All Electrical • Battery discharged or defective Recharge or replace G-26 Equipments Do Not Operate • Battery positive cable disconnected or Repair or replace...
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM CHARGING SYSTEM Reference Symptom Probable Cause Solution Page Charging Lamp Does • Fuse blown (15 A) Replace G-36 Not Light When Main • Wiring harness disconnected or improperly Repair or replace –...
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 2. SERVICING SPECIFICATIONS Item Factory Specification Allowable Limit Battery Voltage More than 12 V – Potential Less than 0.1 V – Difference Approx. 0.9 Ω Glow Plug Resistance – Starter Commutator O.D.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-8.) Item N·m kgf·m ft-lbs Starter B terminal nut 5.9 to 11.8...
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM 4. CHECKING, DISASSEMBLING AND SERVICING CAUTION • To avoid accidental short circuit, be sure to attach the positive cable to the positive terminal before the negative cable is attached to the negative terminal.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Battery Specific Gravity 1. Check the specific gravity of the electrolyte in each cell with a hydrometer. 2. When the electrolyte temperature differs from that at which the hydrometer was calibrated, correct the specific gravity reading following the formula mentioned in (Reference).
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [2] STARTING SYSTEM (1) Checking (A) Safety Switches Method of Inspecting Each Control A defective location can be judge by checking function of each safety switch one by one as shown in the table below.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM (B) Main Switch Connector Voltage 1. Remove the rear wheel (RH) and fender under cover. 2. Measure the voltage with a voltmeter across the connector 30 (Red) terminal and chassis. 3. If the voltage differs from the battery voltage (11 to 14 V), the wiring harness is faulty.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM (C) Starter Motor Test CAUTION • Secure the starter to prevent it from jumping up and down while testing the motor. 1. Disconnect the battery negative cable from the battery. 2. Disconnect the battery positive cable and the leads from the starter.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Glow Plug Continuity 1. Disconnect the lead from the glow plugs. 2. Measure the resistance with an ohmmeter between the glow plug terminal and the chassis. 3. If 0 ohm is indicated, the screw at the tip of the glow plug and the housing are short-circuited.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM (F) Fuel Pump Connector Voltage 1. Disconnect the 2P connector from the fuel pump. 2. Turn the main switch key to the “ON” position, and measure the voltage with a voltmeter between the connector terminals.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM (2) Disassembling and Assembling (1) Magnetic Switch Mounting (2) Housing (3) Magnetic Switch (4) C Terminal Nut (5) Shaft Assembly (6) Drive Lever (7) Overrunning Clutch (8) Connecting Lead (9) Mounting Screw...
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Commutator and Mica 1. Check the contact face of the commutator for wear, and grind the commutator with emery paper if it is slightly worn. 2. Measure the commutator O.D. with an outside micrometer at several points.
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ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Armature Coil 1. Check the continuity across the commutator and armature coil core with an ohmmeter. 2. If it conducts, replace the armature. 3. Check the continuity across the segments of the commutaor with an ohmmeter.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [3] CHARGING SYSTEM (1) Checking Battery Charging Current 1. After starting the engine, disconnect the battery positive cord (+), and connect an ammeter and voltmeter. Then switch on all electrical loads (such as head lights) and measure the charging current.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM Rotor 1. Tap out the shaft (1) from the rotor (3). (When reassembling) • Take care the direction of the collar (4), the flat side should face to the pulley (2) side.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [4] LIGHTING SYSTEM (1) Checking Charge Lamp (Charging Circuit) 1. Remove the under panel. 2. Disconnect the 6P connector from the regulator after turning the main switch OFF. 3. Turn the main switch ON and connect a jumper lead from the wiring harness connector terminal (Black) to the chassis.
ELECTRICAL SYSTEM ZD18(F) · ZD21(F) · ZD28(F), WSM [5] GAUGES (1) Checking Fuel Level Sensor 1) Sensor Continuity 1. Remove the fuel level sensor from the fuel tank. 2. Measure the resistance with an ohmmeter across the sensor terminal and its body.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM 2. LIFTING MECHANISM T15060MO00202 (1) Lift Cylinder (3) Rear Arm (4) Horizon Plate (5) Front Arm (2) Lift Shaft The lifting of mower is performed by the hydraulic system on the machine.
ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-9.) Item N·m kgf·m ft-lbs Mower blade screw 98.1 to 117.7...
ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM 4. CHECKING, DISASSEMBLING AND ASSEMBLING [1] CHECKING AND ADJUSTING Adjusting Anti-scalp Rollers IMPORTANT • The flattest cut can be achieved by having the anti-scalp rollers adjusted off the ground. Check anti-scalp roller adjustments each time the mower deck cutting height is changed.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Adjusting Left and Right Cutting Height 1. Wheel pressure must be correct. 2. Raise up the mower deck to the transport position. (Also the top end). 3. Turn the cutting height set dial (1) to the 3 in. cutting height position.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Adjusting Front and Rear Cutting Height 1. Wheel pressure must be correct. 2. Raise up the mower deck to the transport position. (Also the top end). 3. Turn the cutting height set dial (1) to the 3 in. cutting height position.
ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM [2] DISASSEMBLING AND ASSEMBLING Universal Joint and Belt Covers 1. Remove the universal joint (1). 2. Remove the left and right belt covers (2), (3). (1) Universal Joint (3) Belt Cover (Right)
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Gear Box and Mower Belt 1. Turn over the mower. 2. Remove the mower belt (1) from the tension pulley (5). 3. Unscrew the left and right gear box mounting screws (3), (4) and remove the gear box (2) from the mower deck.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Center Pulley Holder 1. Unscrew the center pulley holder screws (5) and reamer screws (10). 2. Remove the upper oil seal (11) and lower oil seal (4). 3. Remove the internal snap ring (3) and ball bearing (2).
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Outer Pulley and Blade Shaft 1. Unscrew the outer pulley mounting nut (20), and remove the outer pulley (23) and feather key (27). 2. Unscrew the pulley holder mounting screws (18), and separate the left pulley holder (29) from the mower deck.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Turning Torque of Pinion Shaft 1. Remove the mower belt, and reassemble the gear box to the mower deck. 2. Wind a string around the pinion shaft and set a spring balance (or push-pull gauge) to the tip of the string, and then slowly pull the spring balance horizontally to measure the turning force.
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ROTARY MOWER ZD18(F) · ZD21(F) · ZD28(F), WSM Backlash between Bevel Gears 1. Remove the gear box cap (3). 2. Place fuses the 19T bevel gear (2) on the pinion shaft (5). 3. Turn the pinion shaft. 4. Take out the fuses, and measure the thickness of fuses with an outside micrometer.
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TO THE READER How to use ZD25F WSM (97897-15220). Attached please find the WSM for ZD25F, which please use together with WSM (No. 97897-15061) already issued for ZD18(F), ZD21(F) and ZD28(F). For your information, the WSM of ZD25F has been prepared newly by adding the information contained in the Sections of specifications, dimensions, general and engine.
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CONTENTS SPECIFICATIONS ....................1 DIMENSIONS ......................3 G. GENERAL ....................... G-1 1. ENGINE......................1-S1 SERVICING....................1-S1 KiSC issued 04, 2009 A...
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SPECIFICATIONS ZD25F, WSM SPECIFICATIONS Model ZD25F Maximum gross power 18.7 kW (25 HP)* Model D1005-E2-ZD Type Indirect injection, vertical, water cooled, 4-cycle diesel engine Number of cylinders 76.0 × 73.6 mm (2.99 × 2.90 in.) Bore and stroke Total displacement 1001 cm (61.1 cu.in.)
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Fabricated Weight (With mower deck) 753 kg (1660 lbs) / With 60" mower deck deck Shaft drive KUBOTA 10 tooth in spline (2530 rpm) PTO clutch Wet multi discs Revolution (PTO speed) 1 speed (2540 rpm at 3000 engine rpm)
G GENERAL ZD25F, WSM 1. IDENTIFICATION When contacting your local KUBOTA distributor, always specify engine serial number (3), machine serial number (2), mower serial number (4) and hour meter reading. (1) Machine Identification Plate (4) Mower Serial Number (2) Machine Serial Number...
Screws, bolts and nuts should be installed in their original position to prevent reassembly errors. • When special tools are required, use KUBOTA genuine special tools. Special tools which are not frequently used should be made according to the drawings provided.
G GENERAL ZD25F, WSM 3. HANDLING PRECAUTIONS FOR ELECTRICAL PARTS AND WIRING To ensure safety and prevent damage to the machine and surrounding equipment, heed the following precautions in handling electrical parts and wiring. IMPORTANT • Check electrical wiring damage loosened connection every year.
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G GENERAL ZD25F, WSM • Securely clamp, being careful not to damage wiring. (1) Clamp (3) Clamp • Wind Clamp Spirally (4) Welding Dent (2) Wire Harness W1011458 • Clamp wiring so that there is no twist, unnecessary sag, or excessive tension, except for movable part, where sag be required.
G GENERAL ZD25F, WSM [2] BATTERY • Take care not to confuse positive and negative terminal posts. • When removing battery cables, disconnect negative cable first. When installing battery cables, check for polarity and connect positive cable first. • Do not install any battery with capacity other than is specified (Ah).
G GENERAL ZD25F, WSM • Use sandpaper to remove rust from terminals. • Repair deformed terminal. Make certain there is no terminal being exposed or displaced. (1) Exposed Terminal (3) Sandpaper (2) Bend Terminal (4) Rust W1012346 • Make certain that there is no female connector being too open.
10W-40 Above 25 °C (77 °F) : SAE30, 10W-30 or 10W-40 3.2 L Transmission case 3.4 U.S.qts. 2.8 Imp.qts. KUBOTA UDT or SUPER UDT fluid* 4.0 L Transmission case 4.2 U.S.qts. with filter and hose 3.5 Imp.qts. 1.8 L each...
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The oil used to lubricate the transmission is also used as hydraulic fluid. To insure proper operation of the hydraulic system and complete lubrication of the transmission, it is important that a multi-grade transmission fluid be used in this system. We recommend the use of KUBOTA UDT or SUPER UDT fluid for optimum protection and performance.
G GENERAL ZD25F, WSM 5. TIGHTENING TORQUES [1] GENERAL USE SCREWS, BOLTS AND NUTS Screws, bolts, and nuts whose tightening torques are not specified in this Workshop Manual should be tightened according to the table below. Indication on top of...
G GENERAL ZD25F, WSM [3] METRIC SCREWS, BOLTS AND NUTS Grade Property class 8.8 Property class 10.9 Unit Nominal Diameter N·m kgf·m ft-lbs N·m kgf·m ft-lbs 23.6 to 27.4 2.4 to 2.8 17.4 to 20.2 29.4 to 34.3 3.0 to 3.5 21.7 to 25.3...
G GENERAL ZD25F, WSM 6. MAINTENANCE CHECK LIST After Service interval Period purchase Impor- Reference tant page Items year years Engine oil Change G-17 Engine oil filter Replace G-17 Transmission fluid Change G-19 Transmission oil filter Replace G-18 Transmission strainer...
G GENERAL ZD25F, WSM 7. CHECK AND MAINTENANCE CAUTION • Be sure to check and service the machine on a flat place with engine shut off, the parking brake on and chock the wheels. [1] DAILY CHECK To prevent trouble from occurring, it is important to know the condition of the machine. Check the following items before starting.
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G GENERAL ZD25F, WSM Checking Tire Pressure WARNING To avoid personal injury: • Do not attempt to mount a tire on a rim. This should be done by a qualified person with the proper equipment. • Always maintain the correct tire pressure.
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G GENERAL ZD25F, WSM Checking Coolant Level CAUTION To avoid personal injury: • Do not remove the radiator cap when the engine is hot. Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely.
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G GENERAL ZD25F, WSM Checking and Cleaning Radiator to Prevent Overheating CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before cleaning. Daily or after every 5 hours of operation, check to be sure the radiator screen and radiator core are clean.
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G GENERAL ZD25F, WSM Greasing (Mower) CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before greasing. 1. Apply grease to the following position as figures. (1) Mower Universal Joint (4) Belt Tension Pivot...
IMPORTANT • To prevent serious damage to the engine, element of recommended type must be used. Use only a genuine KUBOTA filter or its equivalent. (1) Engine Oil Filter Cartridge W1030949 G-17 KiSC issued 04, 2009 A...
IMPORTANT • To prevent serious damage to hydraulic system, the replacement filter must be a highly efficient, 10 μm filter. Use only a genuine KUBOTA filter or its equivalent. (1) Transmission Oil Filter Cartridge (2) Screw W1031068...
G GENERAL ZD25F, WSM [4] CHECKING POINTS OF INITIAL 200 HOURS Changing Transmission Fluid CAUTION • Be sure to stop the engine before changing the transmission fluid. 1. Place an oil pan underneath the transmission case. 2. Remove the drain plugs (1) at the bottom of the transmission case and drain the oil completely.
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G GENERAL ZD25F, WSM Changing Rear Axle Case Oil (RH and LH) CAUTION • Be sure to stop the engine before changing the transmission fluid. 1. Place an oil pan underneath the rear axle gear case. 2. Remove the drain plugs (1) at the bottom of the transmission case and drain the oil completely.
G GENERAL ZD25F, WSM [5] CHECK POINTS OF EVERY 50 HOURS Checking Safety Device CAUTION To avoid personal injury: • Do not allow anyone near the machine while testing. • If the machine does not pass one of the following tests, do not operate the machine.
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G GENERAL ZD25F, WSM Test 6 (OPERATOR ON THE SEAT) 1. Start the engine. 2. Do not set the parking brake. 3. Shift the PTO lever (4) to “DISENGAGE” (OFF) position. 4. Grasp the motion control levers (3) and move then inward from “NEUTRAL LOCK”...
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G GENERAL ZD25F, WSM Greasing 1. Apply a grease to the following position as figures. CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before greasing. (1) King Pin (LH · RH) (5) Motion Control Levers (LH · RH)
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G GENERAL ZD25F, WSM Greasing (Continued) 1. Apply a grease to the following position as figures. CAUTION To avoid personal injury: • Be sure to stop the engine and remove the key before greasing. (1) Machine Universal Joint (2) Throttle Cable (Oil)
G GENERAL ZD25F, WSM Checking Gear Box Oil Level CAUTION To avoid personal injury: • Always stop the engine and remove the key before checking oil. 1. Park the machine on a flat surface and lower the mower to the ground.
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G GENERAL ZD25F, WSM Battery Charging DANGER To avoid serious injury or death: • When the battery is being activated, hydrogen and oxygen gases in the battery are extremely explosive. Keep open sparks and flames away from the battery at all times, especially when charging the battery.
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G GENERAL ZD25F, WSM Checking Fuel Lines And Fuel Filter CAUTION • Be sure to stop the engine and remove the key when attempting to make the following checks and changes. • Never fail to check the fuel lines periodically. The fuel lines are subject to wear and age.
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G GENERAL ZD25F, WSM Checking Parking Brake CAUTION To avoid personal injury: • Stop the engine and chock the wheels before checking or adjusting. • Park the machine on a hard and level surface. IMPORTANT • Wrong adjustment may cause machine damage.
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G GENERAL ZD25F, WSM Adjustment of brake spring play 1. Place the motion control lever to “NEUTRAL LOCK” position. 2. Be sure to chock the rear wheels. 3. Release the parking brake. 4. Loosen the lock nuts. 5. Pull the brake rod fully forward by hand and hold.
G GENERAL ZD25F, WSM [7] CHECK POINTS OF EVERY 150 HOURS Changing Mower Gear Box Oil 1. See page G-25. W1036280 [8] CHECK POINTS OF EVERY 200 HOURS Adjusting Front Axle Pivot 1. See page G-18. W1064227 Checking Radiator Hose and Clamp NOTE •...
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G GENERAL ZD25F, WSM Adjusting the Motion Control Lever Pivot CAUTION To avoid personal injury: • Be sure to stop the engine and set the parking brake to “ON” before checking. 2 to 15 mm Lever free travel (A) Factory spec.
G GENERAL ZD25F, WSM [9] CHECK POINTS OF EVERY 400 HOURS Replacing Fuel Filter 1. Disconnect the fuel hoses and loosen the filter band to replace the fuel filter (2). NOTE • If the fuel line is removed, be sure to properly bleed the fuel system.
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G GENERAL ZD25F, WSM Flushing Cooling System and Changing Coolant CAUTION • Do not remove the radiator cap when the engine is hot. Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely. 1. Stop the engine and let cool down.
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G GENERAL ZD25F, WSM Flushing Cooling System and Changing Coolant (Continued) Anti-Freeze If coolant freezes, the cylinders and radiator can be damaged. It is necessary, if the ambient temperature falls below 0 °C (32 °F), to remove coolant mix it with anti-freeze and full the radiator with 1.
G GENERAL ZD25F, WSM [11] CHECK POINT OF EVERY 2 YEARS Replacing Hydraulic Hose 1. Replace the hose. Refer to “Checking Hydraulic Hose”. (See page G-30.) W1067327 Replacing Radiator Hose 1. Replace the hoses and clamps. Refer to “Checking Radiator Hose and Hose Clamp”. (See page G-30.)
G GENERAL ZD25F, WSM [12] OTHERS Replacing Fuses 1. The electrical system is protected from potential damage by fuses. A blown fuse indicates that there is an overload or short somewhere in the electrical system. 2. If any of the fuses should blow, replace with a new one of the same capacity.
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G GENERAL ZD25F, WSM Checking Mower Blade and Replacing Mower Blade 1. Check the cutting edge of mower blade. 2. Sharpen the cutting edges, if the mower blades are as shown in figure (2). 3. Replace the mower blades, if they are as shown in figure (3).
G GENERAL ZD25F, WSM 8. SPECIAL TOOLS [1] SPECIAL TOOLS FOR ENGINE Special Use Puller Set Code No: 07916-09032 Application: Use exclusively for pushing out bearing, gears and other parts with ease. W1048293 Piston Ring Compressor Code No: 07909-32111 Application: Use exclusively for pushing in the piston with piston rings into the cylinder.
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G GENERAL ZD25F, WSM Nozzle Tester Code No: 07909-31361 Application: Use to check the fuel injection pressure and spray pattern of nozzle. Measuring: 0 to 50 MPa range (0 to 500 kgf/cm , 0 to 7000 psi) W1049783 Plastigage Code No:...
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G GENERAL ZD25F, WSM Injection Pump Pressure Tester Application: Use to check fuel tightness of injection pumps. Pressure gauge full scale: More than 29.4 MPa (300 kgf/cm , 4267 psi) Copper gasket Flange (Material: Steel) Hex. nut 27 mm (1.06 in.) across the plat...
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G GENERAL ZD25F, WSM Bushing Replacing Tool Application: Use to press out and to press fit the bushing. 1. For small end bushing 157 mm (6.1811 in.) 24 mm (0.9449 in.) 120 mm (4.7244 in.) 21.8 to 21.9 mm dia. (0.8583 to 0.8622 in. dia.) 24.8 to 24.9 mm dia.
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G GENERAL ZD25F, WSM Crankshaft Bearing 1 Replacing Tool Application: Use to press out and to press fit the crankshaft bearing [Press Out] 135 mm (5.31 in.) 72 mm (2.83 in.) 1.57 rad. (40°) 10 mm (0.39 in.) 22 mm (0.87 in.) 20 mm dia.
G GENERAL ZD25F, WSM [2] SPECIAL TOOLS FOR MACHINE Relief Valve Pressure Tester Code No: 07916-50045 Application: This allows easy measurement of relief set pressure. (1) Gauge (07916-50322) (6) Adaptor C (PS3/8) (07916-50371) (2) Cable (07916-50331) (7) Adaptor D (PT1/8) (07916-50381)
ENGINE ZD25F, WSM 1. TROUBLESHOOTING Reference Symptom Probable Cause Solution Page Engine Does Not • No fuel Replenish fuel – Start • Air in the fuel system Bleed fuel system – • Water in the fuel system Change fuel and –...
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ENGINE ZD25F, WSM Reference Symptom Probable Cause Solution Page Engine Revolution Is • Fuel filter clogged or dirty Replace fuel filter G-32 Not Smooth • Air cleaner clogged Clean or replace air G-24 cleaner element. • Fuel leak due to loose injection pipe retaining...
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ENGINE ZD25F, WSM Reference Symptom Probable Cause Solution Page Fuel Mixed into • Injection pump’s plunger worn Replace pump 1-S22 Lubricant Oil element or injection pump • Deficient nozzle injection Repair or replace 1-S52 nozzle • Injection pump broken Replace injection...
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ENGINE ZD25F, WSM Reference Symptom Probable Cause Solution Page Engine Overheated • Engine oil insufficient Replenish engine oil G-17 • Fan belt broken or tensioned improperly Replace fan belt or G-27, adjust fan belt 1-S14 tension • Coolant insufficient Replenish coolant –...
ENGINE ZD25F, WSM 2. SERVICING SPECIFICATIONS [D1005-E2-ZD] [1] ENGINE BODY Item Factory Specification Allowable Limit Cylinder Head Surface Flatness – 0.05 mm 0.0020 in. Top Clearance 0.55 to 0.70 mm – 0.0217 to 0.0276 in. Compression Pressure (When Cranking with Starting Motor) 2.84 to 3.24 MPa...
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ENGINE ZD25F, WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Valve Spring Free Length 37.0 to 37.5 mm 36.5 mm 1.457 to 1.476 in. 1.437 in. Setting Load 117.6 N 100.0 N 12.0 kgf 10.2 kgf 26.4 lbs 22.5 lbs Setting Length 31.0 mm...
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ENGINE ZD25F, WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Timing Gear Crank Gear to Idle Gear Backlash 0.032 to 0.115 mm 0.15 mm 0.0013 to 0.0045 in. 0.0059 in. Idle Gear to Cam Gear Backlash 0.036 to 0.114 mm 0.15 mm...
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ENGINE ZD25F, WSM ENGINE BODY (Continued) Item Factory Specification Allowable Limit Crankshaft Journal to Crankshaft Bearing Oil Clearance 0.034 to 0.114 mm 0.20 mm 0.00134 to 0.00449 in. 0.0079 in. Crankshaft Journal O.D. 47.934 to 47.950 mm – 1.88717 to 1.88779 in.
ENGINE ZD25F, WSM [4] FUEL SYSTEM Item Factory Specification Allowable Limit Injection Pump Injection Timing 0.30 to 0.33 rad – 17.0 to 19.0° before T.D.C. Fuel Injection Nozzle Injection Pressure 13.73 to 14.71 MPa – 140 to 150 kgf/cm 1991 to 2133 psi...
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ENGINE ZD25F, WSM 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts : See page G-9.) Item Size × Pitch N·m kgf·m ft-lbs M6 × 1.0 Starter M terminal nut 9.8 to 13.7...
ENGINE ZD25F, WSM 4. CHECKING, DISASSEMBLING AND SERVICING [1] SEPARATING ENGINE (1) Disassembling and Assembling Draining Engine Oil 1. Park the machine on level ground. 2. Start and warm up the engine for approx. 5 minutes. 3. Place an oil pan underneath the engine.
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ENGINE ZD25F, WSM Draining Coolant CAUTION • Never open the radiator cap while operating or immediately after stopping. Otherwise, hot water will spout out from the radiator. Wait for more than ten minutes to cool the radiator, before opening the cap.
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ENGINE ZD25F, WSM Engine Disassembly 1. Remove the universal joint mounting screws (2). 2. Disconnect the universal joint (3) from fun drive pulley. 3. Remove the engine mounting nuts. 4. Separate the engine with the radiator from the frame, take care not to damage the radiator.
ENGINE ZD25F, WSM [2] ENGINE BODY (1) Checking and Adjusting Compression Pressure 1. Run the engine until it is warmed up. 2. Stop the engine. 3. Disconnect the 2P connector from the fuel pump. 4. Remove the air cleaner, the muffler and all injection nozzles.
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ENGINE ZD25F, WSM Top Clearance 1. Remove the cylinder head. (Do not attempt to remove the cylinder head gasket.) 2. Move the piston up, and stick a strip of fuse [1.5 mm dia. (0.059 in. dia.), 5 to 7 mm long (0.197 to 0.276 in. long)] on the piston head at three positions with grease so as to avoid the intake and exhaust valves and the combustion chamber ports.
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ENGINE ZD25F, WSM Valve Clearance IMPORTANT • The valve clearance must be checked and adjusted when engine is cold. 1. Remove the cylinder head cover and the glow plugs. 2. Align the “1TC” mark (1) on the flywheel and alignment mark (2) on the rear end plate so that the No.
ENGINE ZD25F, WSM (2) Disassembling and Assembling (A) Cylinder Head and Valves Cylinder Head Cover 1. Remove the head cover cap nuts. 2. Remove the cylinder head cover. (When reassembling) • Check to see if the cylinder head cover gasket is not defective.
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ENGINE ZD25F, WSM Removal Procedure for Nozzle Heat Seal Service IMPORTANT • Use a plus (phillips head) screw driver (1) that has a Dia. bigger than the heat seal hole (Approx. 6 mm) 1/4 in.. 1. Drive a screw driver (1) lightly into the heat seal hole.
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ENGINE ZD25F, WSM Tappets 1. Remove the tappets (1) from the crankcase. (When reassembling) • Before installing the tappets, apply engine oil thinly around them. IMPORTANT • Mark the cylinder number to the tappets to prevent interchanging. (1) Tappet W1027457 Valves 1.
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ENGINE ZD25F, WSM Water Pump 1. Remove the water pump flange. (When reassembling) • Before installing the water pump flange gasket, apply liquid gasket (Three Bond 1215 or equivalent) to the both side. W1035410 Gear Case 1. Remove the gear case.
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ENGINE ZD25F, WSM Injection Pump 1. Disconnect the starter spring (4) on the thrust lever side (5). 2. Align the control rack pin (2) with the notch (1) on the crankcase, and remove the injection pump (3). 3. Remove the injection pump shims.
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ENGINE ZD25F, WSM Governor Shaft 1. Remove the pump cover. 2. Remove the external snap ring (1) from the governor shaft (2). 3. Pull out the governor shaft (2). (When reassembling) • Make sure assembling the external snap ring of the governor shaft.
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ENGINE ZD25F, WSM (C) Connecting Rod and Piston Oil Pan and Oil Strainer 1. Remove the oil pan (4). 2. Remove the oil strainer (3). (When reassembling) • Install the oil strainer, using care not to damage the O-ring (1).
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ENGINE ZD25F, WSM Piston 1. Turn the flywheel and bring the No. 1 piston to the top dead center. 2. Pull out the piston upward by lightly tapping it from the bottom of the crankcase with the grip of a hammer.
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ENGINE ZD25F, WSM Piston Ring and Connecting Rod 1. Remove the piston rings using a piston ring tool. 2. Remove the piston pin (1), and separate the connecting rod (7) from the piston (2). (When reassembling) • When installing the rings, assemble the rings so that the manufacturer’s mark (12) near the gap faces the top of the piston.
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ENGINE ZD25F, WSM (D) Crankshaft Flywheel 1. Lock the flywheel not to turn using flywheel stopper. 2. Remove the flywheel screws, except for two which must be loosened and left as they are. 3. Set a flywheel puller (Code No: 07916-32011), and remove the flywheel.
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ENGINE ZD25F, WSM Crankshaft 1. Remove the main bearing case screw 2 (1). 2. Pull out the crankshaft assembly. 3. Turn the crankshaft by 2.09 rad (120°) counterclockwise to set the crank pin of the second cylinder to the bottom dead center.
ENGINE ZD25F, WSM (3) Servicing (A) Cylinder Head and Valve Cylinder Head Surface Flatness 1. Clean the cylinder head surface. 2. Place a straightedge on the cylinder head’s four sides and two diagonal as shown in the figure. 3. Measure the clearance with a feeler gauge.
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ENGINE ZD25F, WSM Clearance between Valve Stem and Valve Guide 1. Remove carbon from the valve guide section. 2. Measure the valve stem O.D. with an outside micrometer. 3. Measure the valve guide I.D. with a small hole gauge, and calculate the clearance.
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ENGINE ZD25F, WSM Valve Seating 1. Coat the valve face lightly with prussian blue and put the valve on its seat to check the contact. 2. If the valve does not seat all the way around the valve seat or the valve contact is less than 70 %, correct the valve seating as follows.
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ENGINE ZD25F, WSM Valve Lapping 1. Apply compound evenly to the valve lapping surface. 2. Insert the valve into the valve guide. Lap the valve onto its seat with a valve flapper or screwdriver. 3. After lapping the valve, wash the compound away and apply oil, then repeat valve lapping with oil.
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ENGINE ZD25F, WSM Oil Clearance between Rocker Arm and Rocker Arm Shaft 1. Measure the rocker arm shaft O.D. with an outside micrometer. 2. Measure the rocker arm I.D. with an inside micrometer, and then calculate the oil clearance. 3. If the oil clearance exceeds the allowable limit, replace the rocker arm and measure the oil clearance again.
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ENGINE ZD25F, WSM (B) Timing Gears, Camshaft and Fuel Camshaft Timing Gear Backlash 1. Set a dial indicator (lever type) with its tip on the gear tooth. 2. Move the gear to measure the backlash, holding its mating gear. 3. If the backlash exceeds the allowable limit, check the oil clearance of the shaft and the gear.
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ENGINE ZD25F, WSM Camshaft Alignment 1. Support the camshaft with V blocks on the surface plate at both end journals. 2. Set a dial indicator with its tip on the intermediate journal. 3. Measure the camshaft alignment. 4. If the measurement exceeds the allowable limit, replace the camshaft.
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ENGINE ZD25F, WSM Oil Clearance between Idle Gear Shaft and Idle Gear Bushing 1. Measure the idle gear shaft O.D. with an outside micrometer. 2. Measure the idle gear bushing I.D. with an inside micrometer, and calculate the oil clearance.
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ENGINE ZD25F, WSM Oil Clearance between Piton Pin and Small End Bushing 1. Measure the piston pin O.D. where it contacts the bushing with an outside micrometer. 2. Measure the small end bushing I.D. with an inside micrometer, and calculate the oil clearance.
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ENGINE ZD25F, WSM Clearance between Piston Ring and Piston Ring Groove 1. Clean the rings and the ring grooves, and install each ring in its groove. 2. Measure the clearance between the ring and the groove with a feeler gauge.
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ENGINE ZD25F, WSM Crankshaft Side Clearance 1. Set a dial indicator with its tip on the end of the crankshaft. 2. Measure the side clearance by moving the crankshaft to the front and rear. 3. If the same size bearing is useless because of the crankshaft journal wear, replace it with an oversize one referring to the table and the figure.
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ENGINE ZD25F, WSM Oil Clearance between Crankpin and Crankpin Bearing 1. Clean the crankpin and crankpin bearing. 2. Put a strip of plastigage (Code No. 07909-30241) on the center of the crankpin. 3. Install the connecting rod cap and tighten the connecting rod screws to the specified torque, and remove the cap again.
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ENGINE ZD25F, WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1 1. Measure the O.D. of the crankshaft front journal with an outside micrometer. 2. Measure the I.D. of the crankshaft bearing 1 with an inside micrometer, and calculate the oil clearance.
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ENGINE ZD25F, WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 and Crankshaft Bearing 3 (To be continued) 1. Put a strip of plastigage (Code No. 07909-30241) on the center of the journal. 2. Install the bearing case and tighten the bearing case screws 1 to the specified torque, and remove the bearing case again.
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ENGINE ZD25F, WSM Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 and Crankshaft Bearing 3 (Continued) (Reference) • Undersize dimensions of crankshaft journal Undersize 0.2 mm 0.4 mm 0.008 in. 0.016 in. Dimension 2.3 to 2.7 mm radius 2.3 to 2.7 mm radius 0.0906 to 0.1063 in.
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ENGINE ZD25F, WSM Correcting Cylinder 1. When the cylinder is worn beyond the allowable limit, bore and hone it to the specified dimension. 76.500 to 76.519 mm Factory spec. 3.01181 to 3.01256 in. Oversized cylinder liner I.D. 76.669 mm Allowable limit 3.01846 in.
ENGINE ZD25F, WSM [3] LUBRICATING SYSTEM (1) Checking Engine Oil Pressure 1. Remove the engine oil pressure switch, and set a oil pressure tester (Code No. 07916-32032). (Adapter screw size : PT 1/8) 2. Start the engine. After warming up, measure the oil pressure of both idling and rated speeds.
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ENGINE ZD25F, WSM Clearance between Rotor and Cover 1. Put a strip of plastigage (Code No. 07909-30241) onto the rotor face with grease. 2. Install the cover and tighten the screws. 3. Remove the cover carefully, and measure the amount of the flattening with the scale and get the clearance.
ENGINE ZD25F, WSM [4] COOLING SYSTEM (1) Checking and Adjusting (A) Fan Belt Fan Belt Tension 1. Measure the deflection (A), depressing the belt halfway between the fan drive pulley and alternator pulley at specified force (98 N, 10 kgf, 22 lbs).
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ENGINE ZD25F, WSM (B) Radiator CAUTION • When removing the radiator cap, wait at least ten minutes after the engine has stopped and cooled down. Otherwise, hot water may gush out, scalding nearby people. Radiator Water Leakage 1. Pour a specified amount of water into the radiator.
ENGINE ZD25F, WSM (2) Disassembling and Assembling Thermostat Assembly 1. Remove the thermostat cover mounting screws, and remove the thermostat cover (1). 2. Remove the thermostat assembly (3). (When reassembling) • Apply a liquid gasket (Three Bond 1215 or equivalent) only at the thermostat cover side of the gasket (2).
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ENGINE ZD25F, WSM [5] FUEL SYSTEM (1) Checking and Adjusting (A) Injection Pump Injection Timing 1. Remove the injection pipes. 2. Remove the engine stop solenoid. 3. Turn the flywheel counterclockwise (facing the flywheel) until fuel flows from the delivery valve holder.
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ENGINE ZD25F, WSM (B) Injection Nozzle CAUTION • Check the injection pressure and condition after confirming that there is nobody standing in the direction the fume goes. If the fume from the nozzle directly contacts the human body, cells may be destroyed and blood poisoning may be caused.
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ENGINE ZD25F, WSM (2) Disassembling and Assembling (A) Injection Nozzle Nozzle Holder 1. Secure the nozzle retaining nut (7) with a vise. 2. Remove the nozzle holder (1), and take out parts inside. (When reassembling) • Assemble the nozzle in clean fuel oil.
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EDITOR : KUBOTA FARM & INDUSTRIAL MACHINERY SERVICE, LTD. 64, ISHIZU-KITAMACHI, SAKAI-KU, SAKAI-CITY, OSAKA, 590-0823, JAPAN PHONE : ( 81 ) 72-241-1129 : ( 81 ) 72-245-2484 E-mail : ks_g.ksos-pub@kubota.com Printed in Japan 2009. 04, S, EI, EI, engusa Code No.9Y011-15062 2001.
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My zd 28 will not cut off at the switch
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