Danfoss T90 Series Service Manual
Danfoss T90 Series Service Manual

Danfoss T90 Series Service Manual

Axial piston pumps
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Summary of Contents for Danfoss T90 Series

  • Page 1 Service Manual Series T90 Axial Piston Pumps www.danfoss.com...
  • Page 2 Service Manual Series T90 Axial Piston Pumps Revision history Table of revisions Date Changed March 2020 1st editiom 0101 © Danfoss | March 2020 AX216086485386en-000101...
  • Page 3: Table Of Contents

    Replace all O-rings and gaskets............................. 5 Safety Precautions....................................6 Unintended Machine Movement............................6 Flammable Cleaning Solvents..............................6 Fluid Under Pressure..................................6 Personal Safety.....................................6 Symbols used in Danfoss literature............................7 Design........................................7 The system circuit.....................................9 The basic closed circuit................................9 Case drain and heat exchanger..............................9 Operation T90 charge pump operation..............................12 T90 charge relief valve operation.............................12...
  • Page 4 3-Position (FNR) electric control............................... 62 Displacement control filter screens............................64 Speed sensor....................................64 Control Module Repair.................................65 Replace control solenoids/actuator housing........................67 Torque chart Fastener size and torque chart..............................68 Plug size and torque chart................................68 Fasteners and plugs..................................69 © Danfoss | March 2020 AX216086485386en-000101...
  • Page 5: Overview

    A worldwide network of Danfoss Global Service Partners (GSPs) is available for major repairs. Danfoss trains GSPs and certifies their facilities on a regular basis. You can locate your nearest ASC using the distributor locator at www.DanfossPower Solutions.com.
  • Page 6: Safety Precautions

    Use proper safety equipment, including safety glasses, at all times. Hazardous Material Hydraulic fluid contains hazardous material. Avoid prolonged contact with hydraulic fluid. Always dispose of used hydraulic fluid according to state, and federal environmental regulations. © Danfoss | March 2020 AX216086485386en-000101...
  • Page 7: Symbols Used In Danfoss Literature

    The legend above defines each symbol and explains its purpose. Design Danfoss Series T90 closed circuit piston pumps convert input torque into hydraulic power. The input shaft transmits rotational force to the cylinder block. Bearings support the input shaft at the front and rear of the pump.
  • Page 8 Series T90 Axial Piston Pumps Introduction Cross section Servo piston Servo arm Piston Slipper Slider block Feedback linkage Bushing Cradle bearing Cylinder block Roller bearing Shaft seal Rear bushing Input shaft Charge pump Swash plate Cradle guide P400621 © Danfoss | March 2020 AX216086485386en-000101...
  • Page 9: The System Circuit

    Fluid routes through the lower drain port on the pump and out the topmost port to the reservoir. A heat exchanger, with a bypass valve, cools the case drain fluid before it returns to the reservoir. © Danfoss | March 2020 AX216086485386en-000101 | 9...
  • Page 10 Motor swashplate Pump swashplate Loop flushing valv e Servo control cyli n der Pump Motor Control flu id Working loop (high pressure) Working loop (low pressur e) Suction line Case drain fluid 10 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 11 Service Manual Series T90 Axial Piston Pumps Introduction Pump schematic P104 126E © Danfoss | March 2020 AX216086485386en-000101 | 11...
  • Page 12: Operation

    These functions are described separately. There are two multi-function valve cartridges in each Series T90 pump to handle functions in either direction. See corresponding sections for adjustments and repairs. 12 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 13: T90 Pressure Limiter/High Pressure Relief Valve Operation

    You can operate the bypass valves to move the vehicle or mechanical function when the pump is not running. Manually resetting the valve position opens the valve. The bypass valves are built into the multi- function valves. © Danfoss | March 2020 AX216086485386en-000101 | 13...
  • Page 14: T90 Speed Sensor Operation

    The servo piston rotates the cradle swashplate through an angular rotation of ±17°, varying the pump’s displacement from full in one direction to full in the opposite direction. The angular position of the pump swashplate is proportional to the rotation of the control input shaft. 14 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 15: T90 Mdc Solenoid Override Valve Operation

    The proportional solenoid applies a force input to the spool, which ports hydraulic pressure to either side of a double acting servo piston. Differential pressure across the servo piston rotates the swashplate, changing the pump‘s displacement from full © Danfoss | March 2020 AX216086485386en-000101 | 15...
  • Page 16: Hcedc Operation

    45 N to engage the plunger. Additional actuations typically require less force to engage the MOR plunger. Proportional control of the pump using the MOR should not be expected. Refer to the control flow table for the relationship of solenoid to direction of flow. 16 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 17 Service Manual Series T90 Axial Piston Pumps Operation P003 204 MOR Schematic diagram (EDC shown) P108758 © Danfoss | March 2020 AX216086485386en-000101 | 17...
  • Page 18: Operating Parameters

    Maximum speed is the highest operating speed permitted. Exceeding maximum speed reduces product life and can cause loss of hydrostatic power and braking capacity. Never exceed the maximum speed limit under any operating conditions. When determining speed limits for a particular application see Danfoss publication BLN-9884 Pressure and speed limits. Warning Unintended vehicle or machine movement hazard Exceeding maximum speed may cause a loss of hydrostatic drive line power and braking capacity.
  • Page 19: T90 Charge Inlet Pressure

    Correct the problem immediately. Inspect vehicle for leaks daily. Change the fluid and filter per the vehicle/machine manufacturer’s recommendations or at the intervals shown in the table. Change fluid after first 500 hours. © Danfoss | March 2020 AX216086485386en-000101 | 19...
  • Page 20 Change filters whenever the fluid is changed or when the filter indicator indicates a filter change. Replace all fluid lost during filter change. For detailed filtration information, see Danfoss publication 520L0463 Fluids and Filtration. For information on biodegradable fluids see Danfoss publication 520L0465 Biodegradable Hydraulic Fluids.
  • Page 21: Technical Specifications

    [lbf•in/1000 psi] [530] [730] [870] Weight (base unit only) [lb] [88] [108] [150] Fluid specifications Ratings and data are based on operation with premium petroleum-based hydraulic fluids containing oxidation and foam inhibitors. © Danfoss | March 2020 AX216086485386en-000101 | 21...
  • Page 22 12-60 1600 [SUS] [47] [66-278] [7500] Temperature °C [°F] -40 [-40] 104 [220] 115 [240] Cleanliness ISO 4406 Class 22/18/13 or better Filtration efficiency suction filtration β35-44=75 (β10≥2) charge filtration β15-20=75 (β10≥10) 22 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 23: Initial Start-Up Procedure

    Normal charge pressure fluctuation may occur during forward and reverse operation. 12. Check that the reservoir is full. Remove charge pressure gauge. The pump is now ready for operation. © Danfoss | March 2020 AX216086485386en-000101 | 23...
  • Page 24: Pressure Measurement

    M2 Speed sensor Charge inlet pressure (vacuum) System pressure gauge port M1 Carge pump inlet port S System pressure Case drain port L2 port A Charge pressure gauge port M3 P106 158E 24 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 25 M6 Port E (before the filter) (from filter) Port D (to filter) Charge pressure gauge port M3 Charge pressure (back side-after gauge port M3 the filter) (after the filter) P106 163E © Danfoss | March 2020 AX216086485386en-000101 | 25...
  • Page 26: Troubleshooting

    If charge pressure decays in one direction, the loop Measure charge pressure in forward and reverse. If pressure flushing valve may be sticking in one direction. decays in one direction, inspect and repair the motor loop flushing valve. 26 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 27: System Will Not Operate In Either Direction

    Internal leakage Internal leakage will reduce system pressure. Check for leaking O-rings, gaskets, and other fittings. Repair unit as required, or replace leaky unit. © Danfoss | March 2020 AX216086485386en-000101 | 27...
  • Page 28: System Noise Or Vibration

    Incorrect charge or control pressures affects system Measure charge and control pressures and correct if performance. necessary. System internal leakage Internal leakage reduces system pressure. Check for leakage in O-rings, gaskets, and other fittings. 28 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 29: Adjustments

    [100 psi] gauge to measure case pressure (tee into L1 or L2 or use servo gauge port M4 or M5). Operate the system with the pump in neutral (zero displacement) when measuring pump charge pressure. © Danfoss | March 2020 AX216086485386en-000101 | 29...
  • Page 30 3. Earlier production Series T90 pumps have a shim adjustable charge pressure relief valve. Shim kits are available from Danfoss. Remove the plug using a 1in hex wrench and exchange shims behind the spring to adjust charge pressure. Torque plug to 68 N•m [50 lbf•ft].
  • Page 31: Multi-Function Valve Pressure Adjustment

    The pressure limiter setting is reached when the pressure stops increasing and remains steady at a given pressure level (as shown on the gauges). © Danfoss | March 2020 AX216086485386en-000101 | 31...
  • Page 32: Engaging The Bypass Function

    Hold the handle in this position during bypass valve operation. 3. To close the bypass valve, tighten the bypass actuator. See table provided for proper torque. Bypass actuator wrench size Frame size Wrench size 055 – 100 1-1/16 inch 32 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 33: Displacement Limiter Adjustment

    4. After establishing the desired maximum displacement setting, torque the lock nut to the torque shown in table below. Displacement limiter adjustment F213 Adjusting screw F212 Lock nut Lock nut torque P106 164E © Danfoss | March 2020 AX216086485386en-000101 | 33...
  • Page 34: Control Neutral Adjustment

    P106 343E 4. Rotate the neutral adjusting screw (M015) clockwise until the pressure increases on the gauge. Note the angular position of the wrench. Then rotate the neutral adjusting screw counter clockwise until 34 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 35: Verify Neutral Setting

    2. If using a PWM signal to set mechanical neutral, start with the electronic control testing tool off (no current/hydraulic pressure to either solenoid). Check to be sure the servo pressure differential is less © Danfoss | March 2020 AX216086485386en-000101 | 35...
  • Page 36: Standard Manual Displacement Control (Mdc) Adjustment

    Service Manual Series T90 Axial Piston Pumps Adjustments than 1.5 bar [22 psi]. Reference Danfoss testing specifications TS-422 or Control Neutral Adjustment instructions. 3. Turn neutral adjusting screw (or supply current/hydraulic pressure to solenoid C2) until the servo pressure at port M5 is less than 1.5 bar [22 psi] greater than at port M4.
  • Page 37 NSS deadband. Ensure the MDC is installed on the pump and in its neutral position when adjusting the neutral start switch eccentric plug. The accompanying drawing provides dimensions for an eccentric plug adjustment tool. © Danfoss | March 2020 AX216086485386en-000101 | 37...
  • Page 38 6. While holding the eccentric plug in place, tighten the eccentric plug lock nut to 27 N•m [20 lbf•ft]. Reinstall and adjust the switch as outlined in the previous section. The eccentric plug normally requires between 5-1/2 and 6-1/2 turns to install into the control housing. 38 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 39 9. If neutral start switch operation is satisfactory, turn off the prime mover, remove the pressure gauges, and reconnect the external control linkage. © Danfoss | March 2020 AX216086485386en-000101 | 39...
  • Page 40: Checking Switch Continuity

    4. Slowly move the control handle in one direction while observing the pressure gauges and the continuity checker. The switch must open before the pressure on either gauge increases more than 1 bar [15 psi] from the base pressure obtained at neutral. 40 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 41: Hydraulic Displacement Control (Hdc) And Electric Displacement Control (Edc) Adjustment

    Note the angular position of the wrench. Rotate the neutral adjusting screw counterclockwise until the pressure increases by an equal amount on the other gauge. Again note the angular position of the wrench. © Danfoss | March 2020 AX216086485386en-000101 | 41...
  • Page 42: Speed Sensor Adjustment

    22° 22° Speed sensor with Speed sensor with packard connector turck connector Shaft centerline 1/2 inch wrench flats 22° 22° Speed sensor with Speed sensor with packard connector turck connector P104 155E 42 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 43: Minor Repair

    You can replace the shaft and seal without major disassembly of the unit. Clean pump and surrounding area thoroughly. Disconnect and remove the pump from the unit, and clean it thoroughly before starting repairs. Mark all connections for later reassembly. © Danfoss | March 2020 AX216086485386en-000101 | 43...
  • Page 44 6. Remove shaft (L100) and roller bearing assembly (L10) from pump. You can transfer the bearing assembly to the new shaft. 7. Using snap-ring pliers, remove the retaining ring (L20) that secures the roller bearing assembly. Remove the roller bearing assembly. 44 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 45 2. Place roller bearing assembly on new shaft and secure with the retaining ring. 3. Install an installation sleeve or wrap spline or keyed end of shaft with plastic film to prevent damage to the sealing lip on the seal during installation. © Danfoss | March 2020 AX216086485386en-000101 | 45...
  • Page 46: Multi-Function Valve Cartridges

    2. Remove and discard O-rings (P13 and P06). 3. Relieve spring pressure by removing bypass actuator (P03), using a 1-1/16 wrench. To retain pressure setting, do not separate adjusting screw (P01), and locknut (P04) from bypass actuator (P03). 46 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 47 If pressure limiter (P01) was removed from bypass actuator (P03), adjust pressure limiter to model code specifications. 5. Install cartridges and torque as shown in the table. Caution Do not overtorque the multi-function valve cartridges © Danfoss | March 2020 AX216086485386en-000101 | 47...
  • Page 48: Charge Pressure Relief Valve

    Remove the screw adjustable charge relief valve plug by loosening the lock nut with a hex wrench corresponding to the table. Lock nut wrench size Frame size Wrench size 055 – 100 1-1/16 inch 48 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 49 52 N•m [38 lbf•ft]. Check the charge pressure and adjust, if necessary. Refer to Charge pressure adjustments. Charge pressure relief valve Lock nut Lock nut torque 1/2 in See appropriate table P106 169E © Danfoss | March 2020 AX216086485386en-000101 | 49...
  • Page 50: Adding An Auxiliary Pad To A Pump Previously Without One

    Ensure that a cover for left hand rotation is used. (See instructions included with the auxiliary pad kit). Orienting the alignment pin Gerotor assembly Alignment pin Left hand rotation (outside look ing into pump) P108929 50 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 51: Auxiliary Pad

    Caution Do not allow the force of the cylinder block spring and swashplate leveler springs to separate the end cap from the pump housing. Gasket damage and external leakage may result. © Danfoss | March 2020 AX216086485386en-000101 | 51...
  • Page 52: Charge Pump

    3. Remove the retainer (H70) and the charge pump cover (J15). Remove and discard O-ring (J40). Note the orientation of the gerotor assembly (H05). Retainer screw wrench size Frame size Wrench size 055 – 100 10 mm 52 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 53 Service Manual Series T90 Axial Piston Pumps Minor repair Current charge pump configuration E101082 © Danfoss | March 2020 AX216086485386en-000101 | 53...
  • Page 54 Series T90 Axial Piston Pumps Minor repair Refer to appropriate Danfoss Series 90 service parts manual for earlier charge pump configurations. 4. Remove the charge pump coupling (H50) and charge pump drive key (H60). 5. Remove the charge pump gerotor assembly (H05).
  • Page 55: Integral Charge Pressure Filter Replacement

    4. Remove the hydraulic tube (N25) from its bore in the endcap. Lock nut wrench size and torque Frame size Wrench size Torque 055 – 100 1-5/8 inch 122 N•m [90 lbf•ft] © Danfoss | March 2020 AX216086485386en-000101 | 55...
  • Page 56 4. Install a new filter canister (N40) per the instructions on the filter canister. Integral charge pressure filter Filter manifold lock nut Lock nut torque N36A 11/16 in 37 N•m [27 lbf•ft] N35A 11/16 in 37 N•m [27 lbf•ft] P106 182E 56 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 57: Pump Control Cover Plate

    (to avoid mixing them up) with a 4mm internal hex wrench. Note the location of each plug, do not interchange plugs. Clean, reinstall, and torque the orifice plugs to 3N•m [2lbf•ft]. © Danfoss | March 2020 AX216086485386en-000101 | 57...
  • Page 58: Displacement Control Orifice Check Valve

    (M1) (with orifice check valve (T40) and spring (T30)) and control gasket (M11) from the housing. Discard the gasket. If necessary, remove the control handle (M70) by removing the locking nut (M72) and washer (M71). 58 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 59 MDC removal/installation 8 mm 1-1/8 in 13.5 N•m [10 lbf•ft] 27 N•m [20 lbf•ft] M90 (x6) 5 mm 16 N•m [12 lbf•ft] Seal washer location (42, 180, 250 cc) P106 185E © Danfoss | March 2020 AX216086485386en-000101 | 59...
  • Page 60: Solenoid Override Valve For Mdc

    3. Using a 4 mm internal hex wrench, remove the four adapter plate mounting screws (M98). Remove the adapter plate and O-rings (M95, M96, and M97) from the control housing. Discard the O-rings. 60 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 61: Hydraulic And Electric Displacement Controls

    Protect exposed surfaces and cavities from damage and foreign material. Reassembly 1. Install a new gasket (M11). Verify the control orifice check valve and spring (T) are in their proper position in the control. © Danfoss | March 2020 AX216086485386en-000101 | 61...
  • Page 62: 3-Position (Fnr) Electric Control

    3. Using a 5 mm internal hex wrench, remove the six adapter plate mounting screws (M90). Remove the adapter plate and gasket (M11) from the housing. Discard the gasket. Caution Protect exposed surfaces and cavities from damage and foreign material. 62 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 63 Install screws (W702). Torque to 5.4 N•m [4 lbf•ft]. FNR removal/installation W702 (x4) 5 mm 5.4 N•m [4 lbf•ft] W701A M90 (x6) 5 mm 16 N•m [12 lbf•ft] M900 Seal washer location (42, 180, 250 cc) P106 185E © Danfoss | March 2020 AX216086485386en-000101 | 63...
  • Page 64: Displacement Control Filter Screens

    13 N•m [10 lbf•ft]. 3. If a speed sensor is not installed, use a 1/4 in internal hex wrench to torque the housing plug (B83) to 40 N•m [30 lbf•ft]. 64 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 65: Control Module Repair

    Ensure that you install the dowel pins (M303) in the housing before installing the control. 6. If you removed screen (D084), install a new one. Install with the mesh facing outward (see drawing). Proper screen orientation P106 519E © Danfoss | March 2020 AX216086485386en-000101 | 65...
  • Page 66 M050 (3X) 4 mm 5 N•m [4 lbf•ft] 5 mm 13.5 N•m [10 lbf•ft] M025 M050 (3X) 4 mm D084 5 N•m [4 lbf•ft] 3 mm 2.5 N•m [1.8 lbf•ft] Torque sequence 66 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 67: Replace Control Solenoids/Actuator Housing

    5. Install solenoid/actuator housing with three cap screws (M90) using a 4 mm internal hex wrench. Torque screws to 5 N•m [4 lbf•ft]. 6. Reconnect electrical/hydraulic connections and test the pump for proper operation. For repair part information, see the Parts Manual for your model. © Danfoss | March 2020 AX216086485386en-000101 | 67...
  • Page 68: Torque Chart

    40 N•m [30 lbf•ft] 7/16-20 3/16 internal hex wrench 12 N•m [9 lbf•ft] G45-G50 9/16-18 11/16 inch hex wrench 40 N•m [30 lbf•ft] G52-G54 9/16-18 1/4 internal hex wrench 23 N•m [17 lbf•ft] 68 | © Danfoss | March 2020 AX216086485386en-000101...
  • Page 69: Fasteners And Plugs

    9/16-18 G49 O-ring plug 9/16-18 G48 O-ring plug 9/16-18 N37 Filter plug assembly F111 / F211 Servo cylinder screw E60 Side cover screw N10 Filter reducer assembly P106 189E P2A1 Multi-function valve © Danfoss | March 2020 AX216086485386en-000101 | 69...
  • Page 70 Phone: +86 21 2080 6201 Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.

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