Kubota u15-3 Workshop Manual
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Kubota u15-3 Workshop Manual

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WORKSHOP MANUAL
KUBOTA EXCAVATOR
U15-3
Code No.97899-61270

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Summary of Contents for Kubota u15-3

  • Page 1 WORKSHOP MANUAL KUBOTA EXCAVATOR U15-3 Code No.97899-61270...
  • Page 2 Record of Revisions Symbol Date Main Revised Points & Corrective Measures Person-in-charge...
  • Page 3 CONTENTS I Product engineering section II Service engineering section...

  • Page 5: Table Of Contents

    WSM U15-3 I Product engineering section A.Developing concept and feature ..... .I-3 a. Objective and Concept of Development ..... . . I-3 b.
  • Page 6 WSM U15-3...

  • Page 7: A.developing Concept And Feature

    WSM U15-3 A.Developing concept and feature a. Objective and Concept of Development 1 Objective of Development Development of products which go ahead of competitive companies in terms of reduced manufacturing costs while reinforcing the performance in horizontal operability, workability, durability, comfort and safety.

  • Page 8: C. Major Selling Points And Improvements

    WSM U15-3 c. Major Selling Points and Improvements 1. Quick chart Inner package of hoses for all attachments Max. excavation capacity increased by 22% Max. excavation depth increased by 10% 4-port ROPS specification Engine start control High-positioned boom cylinder Flat steps...
  • Page 9 WSM U15-3 2. Wrist arm control lever 3. Enlarged foot space U-15 (Previous model) U15-3 (New model) 330mm 460mm 4. Upper positioned boom cylinder 5. Inner package of hoses for front attachments...
  • Page 10 WSM U15-3 6. Engine start control, Travel lock function Unloading lever : UP Engine start Front attachment, traveling Unloading lever : DOWN Engine start Front attachment, traveling 7. 4-post ROPS The equipment is of European specifications.
  • Page 11 WSM U15-3 8. Machine equipped with theft-proof device (Future EU option) Antenna unit Starter key set 9. Side-opening type full-open hood U-15 (Previous model) U15-3 (New model) Paint color and equipment are of European specifications.

  • Page 12: D. Evaluation Of Competitive Power With Competitors

    WSM U15-3 d. Evaluation of Competitive Power with Competitors 1. Workability Current KOMATSU YANMAR Item U15-3 Appealing point in sales U-15 PC15MR Vio15 301.5CR Offence Defense Increase in engine output 11.2 11.3 Max. excavation capacity 15.2 12.5 14.2 13.7 14.4...
  • Page 13 WSM U15-3 3. Operability Current KOMATSU YANMAR Item U15-3 Appealing point in sales U-15 PC15MR Vio15 301.5CR Offence Defense Horizontal operation We will appeal the com- fort and operability of Starter key used also for horizontal operation to higher-ranked models users of current U-15.
  • Page 14 WSM U15-3 7. Working Range U15-3 U-15 Difference Max. excavation depth 2310 2100 +210 Max. vertical excavation depth 1900 1720 +180 Max. excavation radius 3900 3720 +180 Max. excavation height 3540 3740 -200 Max. dumping height 2440 2600 -160 Max. floor excavation radius...

  • Page 15: E. Actual Performance Comparison

    WSM U15-3 e. Actual performance comparison 1. On-site Excavation Test -Test Conditions- 1 m trench excavation, 45-deg. discharge of soil Excavation work for 10 min., (5-min. rotation) The equipment is of European specifications. Increasin U15-3 U-15 PC15MR-1 Vio15-2 301.5CR g rate Volume of soil discharged per hour 31.4...

  • Page 16: B.machine Specifications

    WSM U15-3 B.Machine specifications a. Major dimensions and working range (with rubber crawler) Unit U15-3 Remarks Overall length (at transport) 3570 Overall height (at transport) 2250 Overall width 1240/990 Minimum road clearance Dozer outer width x height 1240/990 x 261...

  • Page 17: B. Dimensional Drawings

    WSM U15-3 b. Dimensional drawings from operator’s manual 410 485 990 620 980 990 3540 2440 2310 1910 1430 2250 2630 265 180 2750 825 3570 3840 3900 1240 1240 (mm) I-13...

  • Page 18: C. Performance And Lifting Capacity

    WSM U15-3 c. Performance and lifting capacity 1. Performance Unit U15-3 Remarks Standard bucket capacity heaped 0.04 CECE Maximum digging force, arm KN(kgf) 8.8 (900) Teeth bottom Maximum digging force, bucket KN(kgf) 15.2 (1550) Teeth bottom Cycle time sec/cycle 10.8 Digging performance 33.4...

  • Page 19: Lifting Capacity

    WSM U15-3 2. Lifting capacity Lifting posture Dozer Unit U15-3 Remarks Crawler extended crawler retracted Maximum lifting capacity (kgf) (standard arm) 215 (T) 215 (T) Down 280 (R) 280 (R) 100 (T) 185 (T) Down 135 (T) 195 (T) 475 (R)
  • Page 20 WSM U15-3 I-16...
  • Page 21 Service port system........II-108 m. Hydraulic components layout : U15-3 ..... . II-111 n.
  • Page 22 WSM U15-3 E.Electrical system....... II-113 a. New Functions of Electric System ......II-113 b.
  • Page 23 WSM U15-3 A.Maintenance specifications a. List of oil and water quantities Unit U15-3 Remarks Radiator soft water Kubota LLC-N-50F Reserve tank soft water Crankcase engine oil Class CC (at filter replacement) 10W30 Hydraulic tank oil ISO 46 Total hydraulic oil...
  • Page 24 WSM U15-3 b. Tightening torque 1. Machine Unit: N m (kgf · · Loctite U15-3 Remarks Travel wheel motor 60.8 ~ 70.6 (6.2 ~ 7.2) Control valve Sprocket 60.8 ~ 70.6 (6.2 ~ 7.2) Track roller 103 ~ 117.7 (10.5 ~ 12) Carrier roller 48.1 ~ 55.9 (4.9 ~ 5.7)
  • Page 25 WSM U15-3 3. Hydraulic pipe tightening torque Steel pipe size (mm) Tightening torque Wrench width (mm) Remarks (O.D. x I.D. x Thickness) N·m (kgf·m) [Reference] 8 x 6 x t1 29.4 ~ 39.2 (3.0 ~ 4.0) 39.2 ~ 44.1 (4.0 ~ 4.5) 10 x 7 x t1.5...
  • Page 26 WSM U15-3 c. Quality specifications Specificatios Items Unit U15-3 Remarks Main Speed JIS A8404 Machine size Total length (Transport) 3575 ± 71 Total width 1240/990 ± 12 Total height (Canopy) 2300 ± 23 Total height (Cabin) Weight Machine weight (Canopy) 1600 ±...
  • Page 27 WSM U15-3 Specificatios Items Unit U15-3 Remarks Front attachment Bucket CECE 0.04 ± 0.002 heaped capacity Bucket width 456 ± 10 Without side cutter Swing angle L 63 ± 2 58 ± 2 Max. digging radius 3901 ± 59 Ground level Max. digging radius mm 3843 ±...
  • Page 28 WSM U15-3 Specificatios Items Unit U15-3 Remarks Travelling performance Travel motor block performance, L/R 300 > 20 deg, 10 min Max, Traction force kgf•m 1255 ± 126 =65% kN•m 12.8 ± 1.3 kgf•m 637 ± 64 kN•m 6.5 ± 0.7 Travel straightness 600 >...
  • Page 29 WSM U15-3 Specificatios Items Unit U15-3 Remarks Hydraulic performance Relief pressure setting kgf/cm +1.0 21.6 - 0.5 +9.8 215.8 - 4.9 kgf/cm +1.0 21.6 - 0.5 +9.8 215.8 - 4.9 kgf/cm +1.0 18.6 - 0.5 +9.8 186.3 - 4.9 kgf/cm +1.0...
  • Page 30 WSM U15-3 Specificatios Items Unit U15-3 Remarks 13 Service port pedal 5.0 ± 1.0 L / R 51.0 ± 10 Boom lever stroke 72 ± 10 Measured grip end down 72 ± 10 Arm lever stroke (crowd/dump) 72 ± 10 Bucket lever stroke (crowd/dump) 74 ±...
  • Page 31 WSM U15-3 d. Operating noise Unit U15-3 Remarks At ear level (Canopy) db(A) 78 > Around the machine db(A) Acoustic power level db(A) 92 > Low-noise specified number Ultra-low noise specified number Emission control specified Standard operation Energy tax system (The noise at ear level is measured with the average energy output under no load at maximum rpm.)
  • Page 32 WSM U15-3 e. Machine weight and parts weight The weights in the table below are approximate. Unit U15-3 Remarks Machine weight 1600 Body weight 1340 Maximum breaker weight Swing bracket and boom cylinder not Backhoe overall included Upper swivel structure...
  • Page 33 WSM U15-3 B.Machine body structure and function a. Overall Arrangement (10) (11) (12) (13) (14) (15) Vertical Operation Service port pedal Fuel tank Control valve (10) Swivel motor Oil cooler (11) Swivel joint Battery (12) Oil tank Radiator (13) Unloading valve...
  • Page 34 WSM U15-3 2. Arrangement of Control Levers Travel lever (left) Control lever for front attachments (left) Lock lever for attachment control Service port pedal Travel lever (right) Control lever for front attachments (right) Two travel speed switch Control lever for dozer or track width...
  • Page 35 WSM U15-3 Horn switch Starter switch Malfunction indicator (Quick Diagnosis) Fuel meter Hour meter Working light switch Adoption of Meters Hour meter, oil level gauge and Easy checker (oil lamp, charge lamp, glow lamp and fuel level alarm lamp) for various indications.
  • Page 36 WSM U15-3 Direction of accel lever : EU - version PP - version (Machine front) Idle Idle (Machine front Starter Switch “STOP“ “RUN“ “START“ Hood Left Oil cooler Hood Rear Radiator Wing nut The oil cooler and the radiator can be checked and cleaned by opening the left hood.
  • Page 37 WSM U15-3 Fuel level gauge Fuel cap cover Air vent Hydraulic oil filler port Gauge • Adoption of fuel level gauge makes it possible to check the remaining oil amount. • A gauge is mounted at the side of the fuel filler port. When fuel is nearly filled up, the pointer of the gauge starts moving and about 2 liters of fuel oil is filled up.
  • Page 38 WSM U15-3 3. Press-fitting of Bushes Positions where bushes and dust seals are inserted (except for the parts finished with bush insertion). Both bush and dust seal Bush only Bucket link 1 side Arm end Bucket link 1 side Arm boss side...
  • Page 39 WSM U15-3 4. Front Equipment Rectify the boom inside. (10) (28) (11) (12) (19) (13) (22) (20) (20)(21) (22) (16) (15) (27) (17) (18) (24) (25) (26) (14) Part Name Q'ty Part Name Q'ty Part No. Bracket (SP) Cushion (1)
  • Page 40 WSM U15-3 5. Greasing (1) (14) (15) (16) (17) (18) (11) (12) (10) (13) Type A (Boss greasing) (10) Type A (Pin greasing) Swing supporting points (upper and lower) Type A (Boss greasing) (11) Type C (Boss greasing) To swivel bearing balls...
  • Page 41 WSM U15-3 6. Greasing (2) Type A (Boss greasing) Type B (Boss greasing) Type B (Boss greasing) A-type: Straight type Type B (Boss greasing) (06611-15010) B-type: 67°C (06616-25010) C-type: 90°C (06616-35010) II-21...
  • Page 42 WSM U15-3 7. Cleaning and greasing the Track Frame Slide Pipes When the slide pipes of the track frame are clogged or adhered with soil or sand, clean the slide pipes in the following manner according to need. WARNING To avoid the personal injury or death: •...
  • Page 43 WSM U15-3 b. Front attachment 1. Bucket dimensions Unit U15-3 Remarks Lip outside width Side cutter outside width 60.5 x 6 139.5 95.5 Arm end width 47.75 (10) (11) (12) (13) (14) 380.5 (15) 48.5 (16) 126.5 (17) 88.5 (18) 16.5...
  • Page 44 WSM U15-3 2. Bucket fixture dimensions Unit U15-3 Remarks 45.3 2 x M12 x 1.25 45.3 45.3 16.5 3.95 167.5 104.5 II-24...
  • Page 45 WSM U15-3 3. Bucket link pin [Unit : mm] Parts name Specifications Bucket link 1 30 x 95.5 Bush A 30 x 38 x W35 Pin A dia 30 x 192.5 Bucket link 2, 3 30 - 30 Arm boss 55 x 38 x L125.5...
  • Page 46 WSM U15-3 4. Front pins and bush [Unit : mm] Location No. Pin diameter x length Bush inner dia. x outer dia. x length Remarks 35 x 257 35 x 45 x 45 35 x 160 35 x 45 x 35, 44...
  • Page 47 WSM U15-3 5. Swing bracket (11) (12) (10) (1) Swing bracket (2) ~ (6) Bushing (7) After installing the bush, pin of 34.9 goes through smoothy. (8) Dimension before bushing. (9) Side of the bush (3) should flash the face.
  • Page 48 WSM U15-3 c. Control levers and linkage 1. Lever strokes and operating forces Reference on new vehicle Unit U15-3 Remarks Stroke Measured at the grip end Boom lever Operating force N(kgf) 13.7 (1.4) Measured 20 mm below the grip end >...
  • Page 49 WSM U15-3 2. Accelerator Lever Set the automatic release function at more than 1200 rpm by idling. (17) (18) Part Name Q'ty Part Name Q'ty Remarks Bracket (Operation, R) Bolt Lever assembly (Accelerator) (10) Lever (Accelerator) (11) Cable (Accelerator) Bush...
  • Page 50 WSM U15-3 3. Dozer Lever Part Name Q'ty Remarks Lever assembly (Blade) Lever (Blade) Bush Grip Seal (Lever, blade) Cable (Blade) Plain washer Snap pin Bracket (Cable, blade) Dimensions in the parentheses show the design values. II-30...
  • Page 51 WSM U15-3 4. Dozer Cables (Route) RA221-6573 Cable (Blade) Pass the cable behind the welded member of the bracket (muffler). Pass the cable along the inside of the welded member of the swivel frame. Pass the cable through the 2 holes of the vertical ribs at the left side of the swivel frame.
  • Page 52 WSM U15-3 5. Swing Pedal (273.5) Reference value Part Name Q'ty Part Name Q'ty Lever assembly (Swing) Plain washer Lever (Swing) Snap pin Bush Lever assembly (Swing pedal) Plain washer Lever (Swing pedal) Snap pin Bush Rod (Swing) Pedal Rod end right-hand screw...
  • Page 53 WSM U15-3 6. Swing Pedal Part Name Q'ty Lever assembly (SP pedal) Lever (SP pedal) Bush Pedal Bolt Plain washer Jam nut Rod (SP) Rod end right-hand screw Spring washer Plain washer Snap pin Assemble so that the pedal upper side should be level at neutral.
  • Page 54 WSM U15-3 d. Under carriage components 1. Swivel bearing (1) Seal B (2) S-mark (3) Seal A (4) R 1/8, for grease nipple Apply the nylon plug in position. 1) Number of teeth = 73 Details of the grease fitting Plug outer soft zone 2) Backlash = 0.05 ~ 0.35 mm...
  • Page 55 WSM U15-3 2. Truck Frame (Adjustment of Play) Play adjusting setbolts at 2 positions on the machine backside. Magnified view of adjusting portion or less (Set bolt) Part Name Q'ty Set bolt (RA221-21161) Play adjusting procedure 1. Tighten the play adjusting setbolts until they reach the left and right sides of the frame.
  • Page 56 WSM U15-3 3. Structure of Track Roller Part Name Q'ty Remarks (1) Track roller FCD600 (2) Shaft (Track roller) S45C-D (3) Ball bearing (4) Bracket (1) FCD450-10 (5) Bracket (2) FCD450-10 (6) O-ring (7) Seal (Floating) (8) Shaft circlip (9) Plug (R1/8)
  • Page 57 WSM U15-3 4. Tension Device Both iron and rubber springs can be used compatively. Part Name Q'ty Idler assembly Cylinder assembly (Left) Cylinder assembly (Right) Nipple (Grease cylinder) In the case of rubber roller, adjust it so that the joint mark ( ) should come to the upper cen- ter position (as shown in the figure below).
  • Page 58 WSM U15-3 5. Idler and tension spring [mm] (1) Support 1 (5) Floating seal (9) Wire (13) Retainer (2) Support 2 (6) Bushing (10) Plug, R 1/8 (14) Nut (3) shaft (7) O-ring (11) Yoke (15) Split pin (4) Idler...
  • Page 59 WSM U15-3 6. Idler and sprocket (A) Reference on new vehicle (B) Allowable limit Unit U15-3 Remarks 202/196 Rubber Crawler Idler (A)/(B) (a) Outside diameter 196/190 Steel Crawler (b) Guide width (A)/(B) 27/23 (c) Idler width (A)/(B) 60/55 Sprocket (A)/(B)
  • Page 60 WSM U15-3 7. Rubber track Spec items Type 230 x 35 x 96 Lug height 23.0 mm Iron core pitch 96.0 mm Circunference 3360 ± 10 mm Number of steel cords 48 ± 4 Steel cords lap length 260 mm Steel cords strength 3.92 KN (400 kgf) or more...
  • Page 61 WSM U15-3 8. Track shoe (A) Reference on new machine (B) Allowable limit Crawler width Unit U15-3 Remarks Length (A)/(B) 360/370 Wheel tread height (A)/(B) 56/51 Collar outside diameter 22/20.5 Collar inside diameter 14/16 Master pin outside diameter 14/12.5 Grouser height (A)/(B) 16.5/8...
  • Page 62 WSM U15-3 9. Iron track shoe (Link) (Bushing) (Bushing) (Link) Over 25 (Pin) (when assembled) (Inside) (Common for both ends) (Outside) Rubber pad (Inside) (Common for both ends) (Outside) Tighten hex nuts to torque of 70-100 N·m. II-42...
  • Page 63 WSM U15-3 9. Dozer Unit U15-3 Remarks Pin outside dia. - Length 30-102.5 Outside diameter - Length 30-84.5 Outside diameter - Length 30-84.5 Outside diameter - Length 30-95 Track cylinder mounting pin Outside diameter - Length 25-133 Extension blade mounting pin...
  • Page 64 WSM U15-3 C.Engine a. Main specification Main specifications of the D782-BH-4 high-speed diesel engine Type 4-cycle, vertical, 3-cylinder, water-cooled diesel engine No. of cylinders - Cylinder bore x Stroke 3 - 67 x L73.6 Piston displacement 0.778 Rated net output/rpm kW / rpm 9.6 (13.1PS) / 2300...
  • Page 65 WSM U15-3 b. Performance curves II-45...
  • Page 66 WSM U15-3 c. Engine electrical data Unit U15-3 Remarks Fuel system Bosch MD (NC), Mini-Pump Injection P type Fuel tank capacity Fuel consumption rate g/kWh Calculated 0.85, Fuel consumption L/hr 19.3 (2.0) 0.6(actual measurement) Type of nozzle DN4PD62 Denso Injection pressure 13.8 ~ 14.7 (140 ~ 150)
  • Page 67 WSM U15-3 d. Engine servicing data (A) Reference on new vehicle (B) Allowable limit Unit U15-3 Remarks Engine model D782-BH-4 Cylinder head distortion limit 0.05 Top clearance 0.50 ~ 0.65 Cylinder bore (A)/(B) 67.000 ~ 67.019 / +0.15 Cylinder liner wear limit +0.15...
  • Page 68 WSM U15-3 e. Engine Mount Vibration-proof rubber Cover (Rubber sheet) Rounded part Bracket (Engine, rear) Stopper (Engine) Bracket (Engine, rear) Vibration-proof rubber II-48...
  • Page 69 WSM U15-3 f. Fuel System 1. Fuel System (1) Type of pipe clip Route of fuel hose (11) * mark 14911-42751 (10) # mark 14971-42751 (12) (13) (14) (15) (16) (17) Can be operated for 8 hours (18) by 18 liters of fuel oil.
  • Page 70 WSM U15-3 2. Fuel System (2) (10) (11) (12) (13) (16) (17) (14) (18) (15) Water separator (10) Engine fuel return port Filter assembly (Fuel) (11) Pass it through this hole. Pump assembly (Fuel) (12) Fuel tank upper part Fuel tank (Upper)

  • Page 71: Fuel Tank

    WSM U15-3 3. Fuel tank Note: No leak is allowed under air pressure of 29.4 kPa Fuel tank (0.3 kg/cm ) in following conditions. Cap assembly (fuel) Fluid in use: Light oil Cap (fuel) Ambient operating temperature: -17 to 70 °C...
  • Page 72 WSM U15-3 g. Cooling system 1. Structure Clamp Cap (pressure) Hole Through II-52...
  • Page 73 WSM U15-3 2. Radiator specifications Heading Unit (Conventional unit) Performance specifications Condition Air flow Vater flow L/min Temp difference °C Radiator capacity 20.7 (17853 kcal/h) Air resisyance 132.3 (13.5 mmAg) Water resistance mmHg) Valve opening pressure Press 147 (1.5 kgf/cm...
  • Page 74 WSM U15-3 h. Air cleaner 129 (Element draw-out allowance) 55 (Cap draw-out allowance) Item Unit Standard Conditions Specifications Air flow resistance Below 2.747 Rated air flow rate: 2.0 m /min. (mmAg) (below 280) Test dust: JIS Z8901, Class 8 powder...
  • Page 75 WSM U15-3 D.Hydraulic system a. Main pump 1. Outer view (1) Suction port (2) 4 - M10 (3) Oil inlet (4) Discharge port (5) Rotation direction, Clockwise 2. Pump coupling II-55...
  • Page 76 WSM U15-3 . Pump hose adapter P1 and P2 are common. Part Name Q'ty Remarks Pump assembly (Piston) Pipe joint (L, G3/8 - G3/8) Pipe joint (L, G3/8 - G3/8) R1/8 P1, P2, P3, P4 Pipe joint (L, G3/8 - G3/8)
  • Page 77 WSM U15-3 4. structure (1) Body S (10) Swash plate (21) Rod G (35) Snap ring (62) Seal washer (2) Body H (11) Needle (24) Retainer (39) O - ring (65) Gear pump (3) Shaft (12) Swing pin (25) Stopper pin...
  • Page 78 WSM U15-3 5. P-Q performance curve Pressure: P (kgf/cm Test condition Remark ISOVG46 3.44 kgf·m Oil temp 50 ± 5 °C (at P =5 kgf/cm 2300 rpm 3.44 kgf·m Direction Clockwise (at P =190 kgf/cm Pump intake torque 4.5 cc/rev 2.7 cc/rev...
  • Page 79 WSM U15-3 6. Pump Specifications, Type : PVD-00B-14P-5G3-4552A, code NO. : RA221-6111 1.Capacity : 7.2 x 2 cm /rev : 4.5 cm /rev : 2.7 cm /rev : 21.6 MPa : 18.6 MPa : 3.9 MPa 2.Pressure at bench (220 kgf/cm...
  • Page 80 WSM U15-3 8. Function 1) Outline Discharge groove P This compact, lightweight hydraulic pump has a Suction groove (1) mechanism that provides for the performance of Discharge groove P two variable pumps. Yet it needs as small a space Suction groove (2) as for just one conventional pump.
  • Page 81 WSM U15-3 b. Control valve 1. Relife valve specifications Type of valve: CP CV NSC10-KP11-2 Manufacturer: Nabco 1) Bench set pressure specifications Product name Remarks Mpa (kgf/cm Main relief valve MRV-P1 · MRV-P2 · MRV-P3 +1.0 P1 · P2 : 21.6 (220 - 0.5...
  • Page 82 WSM U15-3 2. Control Valve (1) Part Name Q'ty Part Name Q'ty Control valve, assembly (17) Elbow pipe joint (G3/8-13) Bolt (18) Straight pipe joint (3-3-35) Shouldered elbow (19) T-pipe joint (F2) Pipe joint (L. G1/4-G1/4) (20) Pipe joint (Bushing G1/4) Pipe joint (L.
  • Page 83 WSM U15-3 3. Control Valve (2) Front Rear II-63...
  • Page 84 WSM U15-3 4.Control Valve (3) Stroke Swing, dozer, service, travel left & right Stroke (mm) II-64...
  • Page 85 WSM U15-3 5. Control Valve (4) Valve specifications • Rated pressure: 22.6 MPa {230 kgf/cm (Under condition of 4 million boost-up actions) Swing • Rated flow rate: 15 L/min • Relief valve set pressure level Dozer : 4.30 ~ 24.5 MPa {50 ~ 250 kgf/cm •...
  • Page 86 WSM U15-3 6. Control valve sectional view 1) Swing section : A-A, RB238-70011 4) Confluence section : D-D, RA221-70911 +0.49 Setting: 18.4 MPa {188 kgf/cm at 10.4 L/min Tightening torque 39.2 N·m Tightening torque T= 3.92 N·m {T= 0.4 kgf·m} {4.0 kgf·m}...
  • Page 87 WSM U15-3 7) Travel R section : G-G, RA221-70061 10)Boom section : J-J, RA221-70071 +0.49 Setting: 17.5 MPa {178 kgf/cm at 5 L/min Tightening torque T= 39.2 N·m {T= 4.0 kgf·m} +0.49 Setting: 27.3 MPa {278 kgf/cm at 5 L/min Tightening torque T= 3.92 N·m {T= 0.4 kgf·m}...
  • Page 88 WSM U15-3 7. Inner sectional view Tightening torque T= 13.7 ~ 14.7 N·m {T= 1.4 ~ 1.5 kgf·m} II-68...
  • Page 89 WSM U15-3 c. Swivel motor 1. Swivel system specifications (A) Reference on new vehicle Unit U15-3 Remarks Maker Eaton Fluid Power Ltd. Type 2-200DOS-E3888 Capacity cc/rev Brake V 13.2 Pressure (135) (kgf/cm Locked L/min Drain spec. Rotating L/min Swivel speed 8.7 ±...
  • Page 90 WSM U15-3 2. Component of swivel motor Part Name Q'ty Remarks Assy motor,swivel Include A ~ R and 020 ~ 220 Assy gear Include A ~ D and 030 ~ 060 Bearing,ball Bearing,ball Plug Retainer Plate Plate,valve Valve Plate Spring...
  • Page 91 WSM U15-3 3. Cross-sectional View of Swivel Motor Part Name Q'ty Remarks Part Name Q'ty Remarks Bearing housing Relief cartridge Include 32 ~ 44 Pinion gear Steel ball Ball bearing 6308 LLU Plug Ball bearing 6207 O-ring 1BP14 Piug R1/8...
  • Page 92 WSM U15-3 . Swivel Motor fittings The outer diameter is same as that of current model. Relief pressure differs. Control valve Front (A3) Control valve Rear (B3) Control valve Rear (T1) Mounting direction Machine front side Part Name Q'ty Remarks...
  • Page 93 WSM U15-3 d. Travel motor (Wheel motor) 1. Overview (RA221-61291) II-73...
  • Page 94 WSM U15-3 2. Specifications (1) Motor type ID mark PHV - 120 - 37 - 9 - 8411A R & D No. Paint class Reduction ratio Nominal output torque NACHI travel motor PHV series (2) Motor specifications Max. theoretical output torque 1st/2nd 1443 N·m (147 kgf·m) / 730N·m (75 kgf·m)
  • Page 95 WSM U15-3 (3) Travel performance specifications Unit U15-3 Remark Type PHV-120-37-9-8411A Climbing performance % / deg. 58 / 30 Maximum traction force KN(kgf) 12.8 ± 1.3 (1255 ± 126) Travel posture, 20°, 10 minutes, engine at = > Travel block performance...
  • Page 96 WSM U15-3 . Piston motor installation Motor (Left) Motor (Right) Part Name Q'ty Drive Sprocket Hex socket bolt Motor, assembly (Wheel) Hex socket bolt Spring washer Pipe joint (S, G1/4-G1/4) Pipe joint (S, G1/8-G1/4) Adaptor O-ring (10) Straight pipe joint...
  • Page 97 WSM U15-3 Structure (1) Counter balance valve (4) Selector valve (2) HI - Lo change valve (5) Hi - Lo piston (3) Selector valve II-77...
  • Page 98 WSM U15-3 4. Principle of operation (1) Operating principle of wheel motor (1) Stationary part (5) Hydraulic motor (2) Rotating part (6) Symple planetary gear reducer (two - step) (3) Counter balance valve (7) Carrier 2 : four planet gears,...
  • Page 99 WSM U15-3 (2) Reducer 1) Function The PHV series travelling motor reducer, which is a simple two-step planetary gear reducer, converts the high-speed revolution of the hydraulic motor to low-speed high torque to obtain case rotation. 2) Description of operation...
  • Page 100 WSM U15-3 (3) Hydraulic motor 1) Function of motor The hydraulic motor, which is an axial piston motor (rotating cylinder and swash plate type), converts the hydraulic energy supplied from the pump to revolving movement. 2) Structure of motor and operating principle (See the figure below.)
  • Page 101 WSM U15-3 3) Operating principle of two-speed motor The swash plate has two faces I and II on the surface opposite to the shoe-sliding surface and sup- ported by the two balls fixed in the body 2 . The ball is positioned eccentrically above the central axis. In the 1st speed state, therefore, the face II is pressed against the body 2 by hydraulic oil force applied to the piston and the spring force in the cylinder barrel and the swash plate angle becomes .
  • Page 102 WSM U15-3 (4) Hydraulic valve (counter balance valve) When the pressure oil is supplied through the port A, the pressure oil pushes open the check valve (3) and flows into the inlet-side port A’ of the hydraulic motor. At the same time, the pressure oil flows through the choke hole C into the room D and slides the spool valve (2) to the right, overcoming the force of spring (4).
  • Page 103 WSM U15-3 e. Pilot valve (Remote control valve) 1. Structure Maker : Kawasaki Precision Machinery Ltd. Type : PV 48 M 2043 A Code No. : RA221-61721 1) Control diagram Single-operating angle Double operating angle Adjust nut (width across flat 22)
  • Page 104 WSM U15-3 2) Specifications 1. Max primary pressure: 6.9 MPa {70 kgf/cm 2. Max. back pressure: 0.3 MPa {3 kgf/cm 3. Rated flow: 15 L/min 4. Secondary pressure characteristics: Refer to the ‘Control diagram’ shown right 5. Operating torque: Refer to the ‘Control diagram’ shown right 6.
  • Page 105 WSM U15-3 2. Sectional view Htdraylic symbol Grease is applied on each rotational part of the universal joint. Pay attention to the direction of assembling the universal joint. Grease is applied on each top part. Part name Casing Plate Shim for adjusting secindary...
  • Page 106 WSM U15-3 3. Adaptors P/V (both right and left) (Quick coupler) Front Rear Left pilot valve Right pilot valve Position for use Color of hose tape Position for use Color of hose tape Swivel Left Bucket raking Pink Arm dumping...
  • Page 107 WSM U15-3 f. Cylinders 1. Cylinder speed (A) Reference on new vehicle (B) Allowable limit Unit U15-3 Remarks Down (A)/(B) 2.2 ± 0.3 MAX to GL Boom cylinder Up (A)/(B) 2.5 ± 0.3 GL to MAX Cushion *0.5 ~1.5 Empty bucket/crowded Crowd (A)/(B) 3.5 ±...
  • Page 108 WSM U15-3 3. Specifications and part codes of boom, arm, bucket and swing cylinder Unit U15-3 Remarks Tube outside diameter - Inside 70-60-30 diameter - Rod outside diameter Stroke Fully retracted Boom Sealing kit part code YW181-9521 N•m 410 ~ 450 Piston tightening torque (kgf•m)
  • Page 109 WSM U15-3 Blade cylinder Unit U15-3 Remarks Tube outside diameter - Inside 70-60-30 diameter - Rod outside diameter Stroke Fully retracted Blade Sealing kit part code YW181-9521 N•m 343.0 ~ 392.0 Piston tightening torque (kgf•m) (35 ~ 40) Piston thread size M22 x 1.5...
  • Page 110 WSM U15-3 5. Cylinders’ section view (Bucket, Arm) T.T. (20) (21) (17) (18) (19) T.T. [mm] (1) Cylinder tube (6) Backup-ring (11) DU-bushing Bucket (2) Cylinder rod (7) Scraper (12) Piston (17) Stroke 335.5 (3) Bushing (8) O-ring (13) Piston seal (18) Retracted L 589 ±...
  • Page 111 WSM U15-3 (Swing) (1)Retracted L = 610 (2)Extended L = 940 (3)Stroke = 330 (Truck) T.T. (1)Retracted L = 478 ± 1.5 (2)Extended L = 728 ± 2.5 (3)Stroke = 250 T.T. : Tightening torque 6. Withstanding external force :...
  • Page 112 WSM U15-3 g. Swivel Joint (Rotary joint) 1. Swivel Joint (1) Part Name Q'ty Remarks Swivel joint, assembly Bolt M12 x 1.25 7T Adapter Pipe joint (L, G1/4-G1/4) Pipe joint (L, G1/4-G1/8) Pipe joint (L, G1/4-10) Pipe joint (L, G3/8-G3/8)
  • Page 113 WSM U15-3 2. Swivel Joint (2) O-rings are added. Part Name Q'ty Remarks Shaft (Swivel joint) Ring (Backup) Ring (D) Ring (Backup) O-ring Collar Body (Swivel joint) Plug (R1/8) Collar (10) Shaft circlip (11) Plug (R1/8) (12) Base (Swivel joint)
  • Page 114 WSM U15-3 3. Route of Hose (Travel, dozer) Route of hose (Swivel joint ~ Travel motor) Dozer Machine left side Left leg Right leg Retractable leg Swivel joint side Travel motor, cyl. Side a. Retractable leg (Retraction) Cyl. rod side Machine right side b.
  • Page 115 WSM U15-3 . Route of Hose (Truck Cylinder Hose) As viewed from below the truck frame (1) Truck cylinder (2) To cyl. rod side (3) To cyl. bottom side (4) Adjust the angle of the adaptor and secure the clearance between the plate of C and the hose to be more than 1 mm and less than 10 mm.
  • Page 116 WSM U15-3 h. Unload valve 1. Structure Maker : Nishina Black (1) Shim (11) Plug (2) spring (12) Hollow bolt (3) Name plate (13) Washer (4) Plunger (14) Screw (5) Spring (15) (6) Spool (16) O-ring (7) Body (17) (8) Solenoid...
  • Page 117 WSM U15-3 3. Adaptor installation (17) (10) (11) (12) (13) (14) (15) (16) Part Name Q'ty Remarks Part Name Valve, assembly (Unloading) Tank cover Straight pipe joint (Drain) (10) PV · Right side P O-ring For G3/8 P (11) PV · Left side P Pipe joint (L.
  • Page 118 WSM U15-3 i. Selector valve 1. Structure 2. Function This valve is to select the oil flow direction for blade cylinder or track cylinder. 3. Specifications 1) Operating pressure and flow : Main relief pressure (20.6 MPa) at 10.4 l/min.
  • Page 119 G 1/2 26 30.02 KX41-3V U15-3 G 3/8 18.6 25.4 Cracking pressure : 196 ± 29 KPa (2 ± 0.3 kgf/cm U15-3 : Check valve = RB238-63802 2. Hydraulic filter Specifications items Suction filter Return filter 1.Filtration area 1650 cm 3600 cm 2.Filtration level...
  • Page 120 WSM U15-3 3. Oil Tank (13) (12) (16) (15) (14) (10) (17) (11) (19) (20) (18) Part Name Q'ty Part Name Oil tank (10) Hose (1/2) Cover (Tank, return) (11) Pump Filter (Return) (12) Unloading valve O-ring (13) Direct the pipe joint (F2) as shown in the figure.
  • Page 121 WSM U15-3 4. Oil cooler Core Hole Core Oil cooler specifications Div. Item Unit Standard Heat radiation kW (kcal/h) 4.81 (4140) Ve=15L/min. t=75 °C.to1=110°C Va=8m/s. Vw=-L/mim Oil-side pressure loss kPa (Kgf/cm Performance specifications Air-side pressure loss Pa (mmAq) Test pressure...
  • Page 122 ) at 20 °C 5. Operating oil temp. : -30 100°C 6. Weight : 1.1 kgf Machine models used : U15-3, U20-3, U25-3 warning It contains nitrogen under high pressure. Don’t allow fire or heat near it. Don’t try to disassem- ble it.Wear eye protection and carefully drill a holl at...
  • Page 123 WSM U15-3 h. Hydraulic system flow 1. Hydraulic Pressure Hose Circuit (High-pressure) (19) (20) (18) (21) (22) Hoses at upper side Position for use Q'ty Part Name Pump (P1)~CV (P1) White (18) Control valve Pump (P2)~CV (P2) White (19) Selector valve Pump (P3)~CV (P3) White (20) Swing cyl.
  • Page 124 WSM U15-3 2. Hydraulic Pressure Hose Circuit (Low-pressure) (12) (13) (10) (11) Low-pressure hoses Position for use Q'ty Part Name (1) Pipe return~Oil cooler Front Oil cooler OUT Control valve (2) CV (T3)~Oil cooler Rear Oil cooler IN Return pipe...
  • Page 125 WSM U15-3 3. Travel Unloading function (10) (11) (1) Bucket (2) Boom (3) Travel Left (4) Supply (5) Travel Right (6) Arm (7) Service (8) Confluence (9) Swivel (10)Dozer (11)Swing With the unload lever being raised, oil of P1 and P2 flows from the supply section directly to the return circuit and results in no functions of P1 and P2 pump, from bucket (1) to service port (7) except pump 3 circuit.
  • Page 126 WSM U15-3 4. Boom Confluence (10) (11) (1) Bucket (2) Boom (3) Travel Left (4) Supply (5) Travel Right (6) Arm (7) Service (8) Confluence (9) Swivel (10)Dozer (11)Swing When boom operation is performed, the boom is operated so that the joint valve is switched over to joint P1 and P3.
  • Page 127 WSM U15-3 6. Straight Travel Circuit (10) (11) (1) Bucket (2) Boom (3) Travel Left (4) Supply (5) Travel Right (6) Arm (7) Service (8) Confluence (9) Swivel (10)Dozer (11)Swing Since only the Boom and Service are jointed with P3, straight travel is possible.
  • Page 128 WSM U15-3 l. Service port system 1. Component layout This pedal is used to operate attachments NOTE: such as breakers. • When the service port is not in use, fold the service port pedal forward. The pedal gets fixed and can be used as footrest.
  • Page 129 WSM U15-3 2. 1-way or 2-way valve The selection valve which select 1-way or 2- way circuit of service port has been installed on the control valve. When the breaker will be used, position the lever of selection valve to the "OPENED"...
  • Page 130 WSM U15-3 II-110...
  • Page 131 WSM U15-3 m.Hydraulic components layout : U15-3 (16) (18) (21) (22) (13) PART NAME Main pump Pilot valve, L (14) Pilot valve, R Accumulater Unload valve Control valve (17) Swivel motor Rotary joint Travel motor, L Travel motor, R Change valve for SP...
  • Page 132 WSM U15-3 n. Hydraulic circuit diagram II-112...
  • Page 133 WSM U15-3 E.Electrical system a. New Functions of Electric System 1. Starter automatic release function When the key is turned ON, the automatic release relay is excited to rotate the starter. When the engine is started (the signal from the engine speed sensor exceeds the set value), the auto- matic release relay is demagnetized to shut down the power to the starter.
  • Page 134 WSM U15-3 b. Battery circuit 1 (AC) 2 (Start) Key SW Cab relay Light SW Stater motor Battery Alternator 1. Keep in mind that the battery voltage is applied through the above circuit all the time. 2. A 60A fuse is added close to the alternator, otherwise part of the harness may get short-circuited due to the alternator's current generated while the engine is running.
  • Page 135 WSM U15-3 c. Key switch (Engine starter switch) Rotor Dust seal 3 water drain Return spring Contact Detent O-ring Key position Start 1st : AC position 2nd : Start position II-115...
  • Page 136 WSM U15-3 d. Safty lever lock switch Part No.:RC411-53473 PVC tube, black stroke Crimp here(4 location) apply silicone resin (1) Plunger (2) (3) (6) (7) (2) Washer (3) Boot (4) Contact plate (5) Body (6) Base comp. (7) Packing (8) Cord...
  • Page 137 WSM U15-3 (2) Safety lever lock circuit malfunction 1) Check battery voltage at (+) terminal of coupler. Check the fuse if no voltage were tested. Upper side solenoid valve is for the safety lock circuit. Lower one is for the travel hi-low function.
  • Page 138 WSM U15-3 e. Solenoid valve Maker : Nishina 1. Structure (1) Shim (11) Plug (2) spring (12) Hollow bolt (3) Name plate (13) Washer (4) Plunger (14) Screw (5) Spring (15) (6) Spool (16) O-ring (7) Body (17) (8) Solenoid...
  • Page 139 WSM U15-3 3. Solenoid test method Solenoid continuity test procedure (In case of diode incorporafed.) Connect the black and red leads to the positive (+) and negative (-) terminals, respectively, of a circuit tester Red lead (pointer type). Make sure the coupler is positioned as shown in the figure.
  • Page 140 WSM U15-3 f. Travel hi-speed control circuit 1. Hi - Low switch and circuit diagram R / G (1) Travel speed switch mark Travel hi- speed switch Hi - Low self - hold circuit Travel speed will increase when pushing down this switch.
  • Page 141 WSM U15-3 3. Testing Hi - Low SW 1) Location of Hi-Low SW coupler and how to disconnect the coupler. Small size driver (match-repair driver) is required. 2) Check battery 12V. 3) Check continuity of the switch. 4) Testing Hi-Low solenoid coil resistance.
  • Page 142 WSM U15-3 4. Hi - Low self hold circuit 1) Lever lock SW isn’t linked. ON-15-2 ON-15-1 (10) Start ON-306-4 ON-306-2 ON-306-3 ON-306-1 ON-800-1 ON-306-2 ON-306-4 ON-801-2 ON-800-1 ON-801-2 ON-306-3 ON-13-2 ON-306-1 ON-13-1 ON-306-2 ON-306-4 ON-306-3 ON-306-1 ON-306-4 ON-306-3 ON-306-2...
  • Page 143 WSM U15-3 3) Key SW is ON and lever lock SW is ON. (10) Start Travel hi-low drive relay Second self-hold relay Travel hi-low solenoid Main Key SW Travel hi-low SW Lever lock SW Negative function relay Self-hold cancel relay...
  • Page 144 WSM U15-3 5) Hand off from the high-low SW button As first self-hold relay (5) is B-type relay, buttery current flows through this normal close contact terminal and activates travel high-low drive relay (1). In this was travel motor keeps running at high speed.
  • Page 145 WSM U15-3 7) Hand off from the travel high-low SW button. (10) Start 8) Pull up the lever lock SW (OFF position) No battery current flows in this system and so the travel motor runs at low speed even after leaving the machine previously at high speed conditions.
  • Page 146 WSM U15-3 9) Function chart : Lever lock SW isn’t wired Key SW (Push & hold) Hi-Low SW (Hand-off) High Hi-Low solenoid 10)Function chart : Lever lock SW is wired Main Key SW Lever lock SW (Push & hold) Hi-Low SW...
  • Page 147 WSM U15-3 g. Meter panel 1. Installation view (1) Meter panel (2) Main key SW (3) Horn SW (4) Hi - Low SW (5) Dozer lever (6) Accel lever (7) Work lamp SW 2. Mater inside view (1) Horn meter...
  • Page 148 WSM U15-3 3. Warning lamps indication Warning Lamp "Engine Oil Pressure" This lamp lights up when there is an abnormality in the engine oil circulation. It lights up when the starter switch is in position “RUN” and goes out as soon as the engine starts running. Should the lamp light up while the engine is running, check the engine oil level.
  • Page 149 WSM U15-3 4. Meter structure Fuel meter (1) Indicator is of movable magnet type (MG-23) and vibration-proof. (2) Performance is as per JIS D5606. (3) The scale graduations other than E, F and 1/2 are dummy. Graduation specifications Graduation (1/2) +7.5...
  • Page 150 WSM U15-3 5. Meter panel circuit diagram ON-1-8 E. Oil Pressure ON-1-2 E. Oil Press Charge ON-1-3 Charge ON-1-5 ON-1-4 ON-1-7 Travel Hi - Lo ON-1-6 Glow ON-1-11 Fuel ON-1-10 ON-1-11 ON-1-12 ON-1-17 1234.5 ON-1-1 Back light ON-1-14 Fuel ON-1-13...
  • Page 151 WSM U15-3 Key SW at ON (AC) position (Engine stop condition) E. Oil switch ON-335-4 ON-1-8 E. Oil Pressure ON-1-2 E. Oil Press ON-28 ON-334-4 Charge ON-1-3 Alternator Charge Start ON-1-5 ON-1-4 ON-1-7 Hi - Lo solenoid Travel Hi - Lo...
  • Page 152 WSM U15-3 6. Fuel gauge coil resistance test Sample data : 86.8 between 3 : 65.8 terminal : 152.6 7. Hour meter function test LED and stepping motor function check. Connect the battery 12V to the white harness and the ground to the black wire.

  • Page 153: Replacing Fuses

    WSM U15-3 h. Fuses 1. Replacing Fuses 3. Slow Blow Fuse 1) Remove the cover of the fuse box. Slow blow fuse is provided to protect the 2) Replace the burnt out fuse with a fuse having electrical circuits. If the fusible link is blown, the same capacity.
  • Page 154 WSM U15-3 i. Auto glow circuit Key st Key on Key SW Glow relay Glow plug Glow lamp Water tempt sensor Battery Auto glow controller 1. Function 1. The glow controller receives a water temperature sensor signal or a key switch start position signal and makes the signal voltage (1) drop to the ground level.
  • Page 155 WSM U15-3 Fig 2. Function chart Key Switch Glow lamp Glow relay Sencor Open ° Water temp ( Fig 3. Timer curve Table 1. Timer function values ° Thermistor resistance ( ) Pre-glow time (sec) Water temp ( 2.55 2.73 2.95...
  • Page 156 WSM U15-3 2. Auto glow control circuit diagram ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (11) (10) (12) ON-17-4 ON-17-3 ON-17-1 ON-17-2 (13) ON-300-3 (16) ON-300-1 ON-300-6 ON-115 (14) ON-300-5...
  • Page 157 WSM U15-3 1) At key ON position : According to the water temp. sensor signal, auto glow controller detects and calculates the required time to glow plugs and supply the current to the glow relay to turn on. Then the battery current flows to the glow plugs and the glow lamp.
  • Page 158 WSM U15-3 2) Key SW at “start“ position : (Engine stop condition) ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (11) (10) (12) ON-17-4 ON-17-3 ON-17-1 ON-17-2 (13) ON-300-3 (16) ON-300-1...
  • Page 159 WSM U15-3 3) After engine start running : ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (11) (10) (12) ON-17-4 ON-17-3 ON-17-1 ON-17-2 (13) ON-300-3 (16) ON-300-1 ON-300-6 ON-115 (14) ON-300-5...
  • Page 160 WSM U15-3 3. Auto glow controller (C/N RC417-53791) 1) If the automatic glow controller seems to malfunc- tion, take it out of the machine, as shown at left, and check the performance of the controller itself referring to the circuit diagram below.
  • Page 161 WSM U15-3 5) Practical inspection Checking the auto glow controller on actual machines Set the key switch to AC position. Make sure the glow lamp lights up. Turn on the key switch and set it to AC position. The lamp does not light up if...
  • Page 162 WSM U15-3 4. Auto glow circuit 1) Water temperature sensor circuit check When the water temperature sensor and its wiring function, the engine’s water temperature is detected and the glow plug is preheated for a time required to get the engine started.
  • Page 163 WSM U15-3 4) Continuity check • Turn the key switch to the OFF position. • Disconnect the meter coupler . • Disconnect the glow relay coupler . 1. Check for continuity between the auto glow relay coupler terminal [CN300-5] and the glow relay coupler CN terminal [CN17-1].
  • Page 164 WSM U15-3 j. Auto release control system 1. Outline 1) When the engine has started and the alternator has reached the specified rpm (N1 = 800 rpm in the fig- ure below), the auto release controller is activated to turn off the auto release relay.
  • Page 165 WSM U15-3 2. Auto relase control, structure and function (1) Battery 12V (2) Main switch (3) Alternator (4) P - terminal (5) Low voltage detection (6) Rotation detection (7) Starter relay (Auto relase lever) 650r/min 800r/min (8) Starter N1 :...
  • Page 166 WSM U15-3 3. Key SW to engine start position ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (13) (10) ON-113 (12) ON-114 ON-25-2 Charge ON-25-3 ON-25-1 (11) Battery Auto release relay...
  • Page 167 WSM U15-3 4. Key SW to AC position ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (13) (10) ON-113 (12) ON-114 ON-25-2 Charge ON-25-3 ON-25-1 (11) Battery Auto release relay Fuse 50A...
  • Page 168 WSM U15-3 5. When the Key SW is stucked at the start position ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (13) (10) ON-113 (12) ON-114 ON-25-2 Charge ON-25-3 ON-25-1 (11)
  • Page 169 WSM U15-3 6. Key to the start position while engine is running ON-14-3 ON-14-1 Start ON-14-2 ON-320-2 ON-320-3 ON-34-2 ON-34-3 ON-320-4 ON-320-1 ON-34-4 ON-34-1 ON-310-2 ON-308-1 ON-310-1 ON-309-1 ON310-4 (13) (10) ON-113 (12) ON-114 ON-25-2 Charge ON-25-3 ON-25-1 (11) Battery...
  • Page 170 WSM U15-3 8. Auto release and auto glow circuit combined Glow plug Glow lamp II-150...
  • Page 171 WSM U15-3 k. Water temp. sensor & gauge Thermister (1) sensor 1. Water temp. sensor circuit malfunction Water temp. sensor signal is sent to the auto glow con- troller. 1) Check couplers Pull the harness to see if the water temperature sen- sor coupler is not out of position.
  • Page 172 WSM U15-3 2) Check battery voltage at (+) terminal of harness cou- pler. If no battery voltage, check the fuse and continuity of wireharness. Sample data is 0.979V. 3) Water temperature sensor check • Disconnect the coupler from the water tempera- ture sensor and measure the resistance referring to the figure at right.
  • Page 173 WSM U15-3 l. Fuel control circuit (1) Function) Fuel pump ON-24-1 ON-24-2 Start ON-335-4 E. Oil switch ON-1-8 E. Oil Pressure ON-1-2 E. Oil Press ON-28 ON-334-4 Charge ON-1-3 Alternator Charge ON-1-5 ON-1-4 ON-1-7 Hi - Lo solenoid Travel Hi - Lo...
  • Page 174 WSM U15-3 m.Engine stop solenoid 1. Structure Specifications 1. Rated voltage :DC12V Suicide switch 2. Rated ampare filter Pull-in coil :32A / DC12V Hold coil :77A / DC12V at 20°C 3. Resistance (Sample data) plunger Pull-in coil : 0.3 ~ 0.8...
  • Page 175 WSM U15-3 3. Engine stop solenoid (C/N 1A021-6001-3) Operation of engine stop solenoid can be test as in the pictures. 1) Connect 12 V battery voltage to two terminal of engine stop solenoid. 2) Get body earth as shown in picture.
  • Page 176 WSM U15-3 n. coil commander 1. Location The coil commander is connected with the engine stop solenoid as shown in the picture. (1) Coil commander Resistance (Sample data) Black : 21.2 White Black : 77.1 2. Circuit diagram Hold (Red)
  • Page 177 WSM U15-3 4. Inspeetion & troubleshooting 1) Check the continuity of hold coil. 2) Check pull in coil function after wiring 12V to red and while terminal and ground to black color termi- nal. Then engine solenoid functions and pull in the plunger head.
  • Page 178 WSM U15-3 o. Fuel sensor 1. Fuel sensor * Insulation resistance: Over 3 M (measured with DC500V megger) (11) (10) (13) (12) (15) (14) (16) (17) (24) (19) (21) (20) Lock collar assembly (13) Connector housing: Sumitomo HM090, water-proof, SPM...
  • Page 179 WSM U15-3 Fuel tank 12V 3.4W Light oil or light oil gas Water or mud deposits possible on flange surface DC 12V DC 10 Float position Full Empty DC14V Resistance ( ) 32.5 Thermister Allowable error ( ) ± 2 ±...
  • Page 180 WSM U15-3 2) Check battery voltage at (+) terminal of wireharness- coupler. If no battery voltage, check the fuse and continuity of wireharness. 3) Fuel sensor check • Apply the positive (+) test lead to the coupler-fitted terminal. • Apply the negative (-) test lead to the plated part to measure the resistance.
  • Page 181 WSM U15-3 p. Engine oil pressure sensor circuit Change Start High - Low Fuel residual 1. Engine oil pressure sensor is N.C.(Normal close) type. 2. Check relay is N.O.(Normal open) type. 3. Meter panel (Big): (1)Engine oil pressure line. (1) In normal...
  • Page 182 WSM U15-3 q. Engine electrical system 1. Engine oil pressure failure 1) Check engine oil pressure lamp. Lamp condition Engine Condition Normal Trouble case (1) Trouble case (2) Before engine starts After engine starts Trouble case (1) :Engine oil pressure is low or oil switch fails.
  • Page 183 WSM U15-3 6) Check engine oil pressure Idling rpm 0.4 MPa(4 kgf/cm MAX. rpm 0.6 MPa(6 kgf/cm • Oil switch operating pressure Oil switch Condition Ref. value:0.05 ± 0.01MPa (0.5 ± 0.1kgf/cm Engine stops Engine Engine starts pressure II-163...
  • Page 184 WSM U15-3 r. Horn circuit 1. Structure (1) Diaphram (5) Stop screw (2) Point (6) Stay (3) Horn coil (7) Air gap (4) Nut The horn consists of acoustic diaphragm, point, horn coil and other parts. It comes in spiral, flat and other types in construction.
  • Page 185 WSM U15-3 3. Current flow (1) Battery (2) Horn switch (3) Horn relay (4) Diaphram (5) Core (6) Coil (7) Moving bolt (8) Adjust nut (9) Moving plate Horn Relay Diode Switch For your information 1. Function of diode: Prevention of horn switch by absorbing the surge current.
  • Page 186 WSM U15-3 4. Horn circuit (Horn SW is off position) • When horn switch is off, current Horn SW doesnít flow through relay. So relay remains off condition and horn doesnít sound. Horn Diode (Horn SW is on position) • When horn switch is on position, cur-...
  • Page 187 WSM U15-3 s. Charging system (Alternator) 1) Alternator structure (Code No. 16678-64012) Nameplate (brown) Terminal B: M6 (Terminal B nut tightening torque (Shaft center reference) (Theoretical value) Nameplate Frame ID projection presettable range Anti-corrosion treatment (1) Pulley (2) Nut (3) Collar, space...
  • Page 188 WSM U15-3 2) Circuit diagram IC regulator Alternator assembly 3) Specifications Standard characteristics Rated voltage 12 V (3.5V constant, ambient temperature 25 °C) Rated output (13.5 V when hot) 40 A (500rpm) Startup rpm (13.5 V when hot) 1350 rpm...
  • Page 189 WSM U15-3 4. Charging system malfunction 1) Check charge lamp condition. Lamp condition Engine Condition Normal Trouble case (1) Trouble case (2) Engine stops Engine starts Trouble case (1):Fan belt breakage, B-terminal failure charging system malfunction. Trouble case (2):Wireharness problem, L-terminal failure 2) Pull the harness to see if the alternator coupler is not out of position.
  • Page 190 WSM U15-3 5) Check battery voltage at B-terminal of wireharness coupler. If no battery voltage, check the fuse and continuity of wireharness. 6) Alternator B-terminal check 1)Measure the voltage between the alternator’s termi- nal B and the body ground. Make sure the measure- ment is 12 V or so.
  • Page 191 WSM U15-3 t. Relay 1. Relays location (N) (G) (H) (I) (J) (K) (L) (A) Starter lock relay (I) Second self hold relay (B) Auto release relay (J) Self hold release relay (C) Auto release stabilizer relay (K) Travel high relay...
  • Page 192 WSM U15-3 3. Structure of relay Fig. in the left shows the sample of relay Starter lock relay (N.C) Code No. : RB419-5371-1 Body Case Coil bin Terminal Iron Core Coil Spring Contact (10) Terminal (11) Terminal (12) Common (13) Terminal...
  • Page 193 WSM U15-3 5. Checking relays 1) When current flows through the coil of a relay, its core is magnetized to attract the iron piece, closing (ON) the con- tact at the tip of the iron piece. When the coil current is turned off, the iron piece is made to return to its original position by a spring, opening the contact (OFF).
  • Page 194 WSM U15-3 u. Route of Electric Wiring 1. Unloading, horn (1) Fix it at 2 positions from inside. (2) Unloading switch (3) Connector (4) Clamp the cable once when it comes out of the hole. (5) Clamp and pass it through the hole 5.5.
  • Page 195 WSM U15-3 2 Route of Electric Wiring (Engine Rear) (12) (11) (10) (1) Theft-proof key setting terminal (2) Key setting connector (3) Slow-blow fuse (4) Direct the fuse box so that the slot comes to the right. (5) Pass the battery cord, dozer cable and wire harness to the theft-proof unit through the hole of the vertical rib.
  • Page 196 WSM U15-3 3. Route of Electric Wiring (Engine Upper Side) (11) (12) (13) (14) (10) (1) Glow, engine stop solenoid (2) Unloading valve, meters, relays, etc. (3) Key setting (4) (Downwards) Power supply, theft-proof unit (5) Fuse (6) Alternator, starter motor...
  • Page 197 WSM U15-3 4. Route of Electric Wiring (Starter Motor, Body Grounding) (1) Cord (Body grounding) (2) Battery cord (Plus) (3) Facing directly below (4) Facing directly above (5) Mount it into the lower hole. (6) Projection (Rear side) (7) Cover (Right)
  • Page 198 WSM U15-3 5. Route of Electric Wiring (Right Side of the Operation Stand) Connect the black relay (T1060-3372 Relay (Starter)) to the black connector and the blue relay (RB419- 5371 Relay (Starter, NC)) to the blue connector. (1) Controller (Auto-glow)
  • Page 199 WSM U15-3 6. Route of Electric Wiring (Front) (1) Connect the red wires and yellow wires in their respective groups and fix them to the working light frame by cord clamps. (2) Clamp the position marked with white tape outside the hole.
  • Page 200 WSM U15-3 II-180...
  • Page 201 WSM U15-3 v. Electrical component layout Key switch panel Horn Relay Controller (Auto Glow) Unload valve Stop solenoid Fuse, slow-blow fuse Back of engine Thermal unit Lock lever limit switch Glow Ground Battery Oil switch Starter motor Fuel sensor Horn...
  • Page 202 WSM U15-3 w. Electric Circuit Lever lock Lever lock switch Key switch Dual-speed Lever lock Automatic release stabilizing relay Automatic release controller Automatic release relay Low-voltage detection Rotation detection Starter Glow relay Auto glow Auto glow controller Glow plug Fuel pump...
  • Page 203 WSM U15-3 1. Battery direct line and ground (Earth) line Lever lock Lever lock switch Key switch Dual-speed Lever lock Automatic release stabilizing relay Automatic release controller Automatic release relay Low-voltage detection Rotation detection Starter Glow relay Auto glow Auto glow controller...
  • Page 204 WSM U15-3 2. Key switch ON (AC - position) Lever lock Lever lock switch Dual-speed Key switch Lever lock Automatic release stabilizing relay Automatic release controller Automatic release relay Low-voltage detection Rotation detection Starter Glow relay Auto glow Auto glow controller...
  • Page 205 WSM U15-3 3. Key switch to the start position Lever lock Lever lock switch Dual-speed Key switch Lever lock Automatic release stabilizing relay Automatic release controller Automatic release relay Low-voltage detection Rotation detection Starter Glow relay Auto glow Auto glow controller...
  • Page 206 WSM U15-3 4. Engine running at travel high renge Lever lock Lever lock switch Dual-speed Key switch Lever lock Automatic release stabilizing relay Automatic release controller Automatic release relay Low-voltage detection Rotation detection Starter Glow relay Auto glow Auto glow controller...
  • Page 207 WSM U15-3 x. Electrical Wiring diagram Japan/EU Japan/EU Japan/EU Soldered to terminals 1 & 3 Japan/EU USA/ (KX91, U35) Japan/EU Japan Japan Japan/EU LA terminal Soldered Soldered LA terminal Battery positive terminal 2004.11.16 II-187...
  • Page 208 WSM U15-3 Japan/EU Japan/EU Japan/EU Soldered to terminals 1 & 3 Japan/EU USA/ (KX91, U35) Japan/EU Japan Japan Japan/EU LA terminal Soldered Soldered LA terminal Battery positive terminal II-188...
  • Page 209 Conversion Tables...
  • Page 212 KUBOTA Corporation CONSTRUCTION MACHINERY DIVISION 1-1-1 NAKAMIYA-OHIKE, HIRAKATA-CITY, OSAKA, JAPAN EDITOR: CONSTRUCTION MACHINERY MANUFACTURING DEPT. SERVICE ENGINEERING SECTION HIRAKATA PLANT 1-1-1 NAKAMIYA-OHIKE, HIRAKATA-CITY, OSAKA, JAPAN PHONE :+81-72-890-2888 :+81-72-890-2886 KUBOTA Corporation Printed in Japan 0503.CMC.e.12 Code No.97899-61270...

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