993K Wheel Loader Electrohydraulic System Caterpillar


Pressure Reducing Valve Pressure for Dead Engine Pilot Supply (Engine OFF) - Test and Adjust

Usage:

993K Z9K

------ WARNING! ------

Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine.

To prevent personal injury or death, perform the following:

Park the machine on a smooth, level surface.

Lower the work tool to the ground and engage the parking brake.

Stop the engine and remove the key.

Block the wheels and install the steering frame lock.


Table 1
Required Tools 
Part Number  Description  Qty 
8T-0850  Pressure Gauge 
1U-5482  Pressure Adapter Group 

The pilot oil for a dead engine is supplied by oil in the lift hydraulic circuit. The pilot oil is used in order to lower the implements to the ground when the engine is off. The high pressure oil in the lift cylinders is reduced by the pressure reducing valve to a reduced pilot oil pressure. The reduced pilot oil pressure must be less than the pilot pump oil pressure.



Illustration 1g01629428
Diagnostic lines
Location of pressure tap for pilot supply oil

The diagnostic lines are located on the loader frame to the right of the articulation joint.

  1. Connect the steering frame lock link.

  2. Attach a 8T-0850 Gauge ( 4000 kPa (580 psi)) to the pressure tap for pilot supply oil.

  3. Engage the parking brake.

  4. Shift the transmission to neutral.

  5. Start the engine. Warm the hydraulic oil to normal operating temperature of approximately 49 to 65°C (120 to 150°F).

  6. Raise the boom off the ground.

  7. Stop the engine. Record the gauge reading.

  8. Turn the key start switch to the ON position and lower the implement to the ground.

  9. The pilot oil pressure for a dead engine should be 1650 ± 150 kPa (240 ± 20 psi).

  10. The pressure control valve must be adjusted if the pilot oil pressure for a dead engine is not correct.


    Illustration 2g01501775
    Main control valve (front view)
    (1) Adjustment screw
    (2) Locknut
    (3) Pressure reducing valve

  11. Loosen locknut (2).

  12. Turn adjustment screw (1) clockwise in order to increase the pilot oil pressure for a dead engine.

  13. Tighten the locknut.

Perform Testing And Adjusting, "Pressure Reducing Valve Pressure for Dead Engine Pilot Supply (Engine OFF) - Test/Adjust" again in order to verify the new setting.

Caterpillar Information System:

953D Track-Type Loader Power Train Steering - Test - Joystick Steering (S-Steer Configuration)
993K Wheel Loader Power Train Modulating Valve (Torque Converter Lockup Clutch)
993K Wheel Loader Power Train Modulating Valve (Torque Converter Impeller Clutch)
D8T Track-Type Tractor Power Train Track Roller Frame
992K Wheel Loader and 854K Wheel Dozer Power Train Transmission Control Valve - Disassemble
D8T and D9T Track-Type Tractors MID 082 - CID 2206 - FMI 03
D8T and D9T Track-Type Tractors MID 082 - CID 2212 - FMI 05
D8T and D9T Track-Type Tractors MID 082 - CID 2212 - FMI 03
992K Wheel Loader and 854K Wheel Dozer Power Train Transmission Control Valve - Install
993K Wheel Loader Power Train Differential
992K Wheel Loader and 854K Wheel Dozer Steering System Pump Performance (Steering) - Test
854K Wheel Dozer and 992K Wheel Loader Radiator Shroud - Remove
854K Wheel Dozer and 992K Wheel Loader Power Train MID 081 - CID 0041 - FMI 04
2007/12/03 A New Fuel Hose and a New Mounting Clip Are Now Used {1274}
993K Wheel Loader Electrohydraulic System Ride Control Signal Pressure - Check
992K Wheel Loader Electrohydraulic System Control Valve (Right)
2008/01/21 An Improved Bolted Joint is Now Available for the Lower Link of the Elevator {6210}
854K Wheel Dozer and 992K Wheel Loader Radiator Shroud - Install
992K Wheel Loader and 854K Wheel Dozer Power Train Transmission Control Valve - Assemble
D8T and D9T Track-Type Tractors MID 082 - CID 2212 - FMI 06
D8T and D9T Track-Type Tractors MID 082 - CID 2213 - FMI 03
D8T and D9T Track-Type Tractors MID 082 - CID 2213 - FMI 05
D8T and D9T Track-Type Tractors MID 082 - CID 2213 - FMI 06
D8T and D9T Track-Type Tractors MID 082 - CID 2214 - FMI 03
Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.