538 Forest Machine Machine Systems Relief Valve (Crossover) - Test and Adjust Caterpillar


Relief Valve (Crossover) - Test and Adjust
`
1.1. Specification
2.1. Introduction
3.1. Required Tools
4.1. Machine Preparation
5.1. Test Procedure
6.1. Adjustment Procedure

Specification

Table 1
"Relief Valve (Crossover) - Test and Adjust" 
Machine Settings  Power Shift Pressure  Engine Speed Dial Position  AEC switch 
1070 ± 50 kPa
(155 ± 7 psi)
1  off 
Item  Direction  Specification  Actual 
Left Travel  Forward  37500 ± 500 kPa (5440 ± 72.5 psi)   
Reverse 37500 ± 500 kPa (5440 ± 72.5 psi)   
Right Travel  Forward  37500 ± 500 kPa (5440 ± 72.5 psi)   
Reverse 37500 ± 500 kPa (5440 ± 72.5 psi)   

Introduction

The crossover relief valves are on the travel counterbalance valves. The following procedure will determine if the crossover relief valves are out of adjustment.

Required Tools



Illustration 1g01623868
Tooling group "B"
198-4240 Digital Pressure Indicator Gp


Illustration 2g03261789
(D) 418-3611 (Track Block)

Table 2
Tool  Item  Part Number  Description  Qty 
198-4240  Digital Pressure Indicator Gp   
  B1  198-4234  Indicator 
B2 198-4239  Pressure Sensor 41,368 kPa (6,000 psi) 
B3 198-4236  Extension Cable 
418-3611  Track Block 

Machine Preparation

  1. Position the machine on level ground.

  2. Stop the engine.

  3. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".


    Illustration 3g03861334
    Pump compartment
    (1) Pressure tap (delivery pressure for drive pump)
    (2) Pressure tap (delivery pressure for idler pump)
    (3) Pressure tap (power shift pressure)

  4. Connect a 41,368 kPa (6,000 psi) pressure sensor to pressure tap (1). Use this pressure sensor to monitor the crossover relief valve pressure setting of the left travel motor.

  5. Connect a 41,368 kPa (6,000 psi) pressure sensor to pressure tap (2). Use this pressure sensor to monitor the crossover relief valve pressure setting of the right travel motor.

  6. Connect a 3445 kPa (500 psi) pressure sensor to pressure tap (3). Use this pressure sensor to monitor the power shift pressure.

Test Procedure

Note: A temporary setting of the main relief valve is required before any crossover relief valve can be adjusted. Refer to Table 3 for the temporary main relief setting for the function being tested.

Note: A continuous relief of the valve for more than 10 seconds is not allowed.

Table 3
Function  Temporary Main Relief Setting 
Left Travel Forward and Reverse  41000 ± 1000 kPa (5950 ± 145 psi) 
Right Travel Forward and Reverse 

Table 4
Relief Valve  Pressure Change With One Turn Of Adjustment Screw 
Main relief valve  14400 kPa (2100 psi) 
Crossover relief valves  3050 kPa (440 psi) 

Note: Pressure values in Table 4 are approximate values. Use a pressure gauge for adjustment.



Illustration 4g02240859
Travel brake valve (left side)
(5) Locknut
(6) Adjustment screw
(7) Crossover relief valve (forward left travel)
(8) Crossover relief valve (reverse left travel)
(9) Locknut
(10) Adjustment screw

  1. Start the engine.

  2. Place the hydraulic activation control lever in the UNLOCKED position.

  3. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

  4. Place the machine controls at the following settings: engine speed dial "10" and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

  5. Move the joystick for the stick until the stick is at the full STICK OUT position (full retraction of stick cylinder).

  6. Check the main relief setting pressure setting at pressure tap (1) and pressure tap (2). The pressure setting should be 35000 + 500 - 1000 kPa (5076 + 73 - 145 psi).

  7. Return the joystick to the NEUTRAL position.


    Illustration 5g02102305
    Main relief valve (standard)
    (A) Adjustment screw
    (L) Locknut


    Illustration 6g02102306
    Main relief valve (heavy lift)
    (A) Adjustment screw
    (L) Locknut

  8. Loosen the locknut. Set the temporary main relief pressure to 41000 ± 1000 kPa (5950 ± 145 psi). Tighten the locknut.

    Note: Turn the adjustment screw clockwise to increase the pressure. Turn the adjustment screw counterclockwise to decrease the pressure.

    Note: Always make final pressure adjustments on pressure rise.

  9. Verify the temporary main relief pressure setting with a second function. Move the joystick for the boom until the boom is at full BOOM RAISE position (full extension of the boom cylinder). The main relief pressure should be 41000 ± 1000 kPa (5950 ± 145 psi).

  10. Enter the service mode.

    1. Input the password "9992".

    2. Select "Override Parameters".

  11. Override "Power Shift Pressure" to 1070 ± 50 kPa (155 ± 7 psi). Confirm the power shift pressure setting at pressure tap (3).

  12. Set the engine speed dial to position "1".


    Illustration 7g03261818
    Sprocket (left travel)
    (D) Track block
    (4) Sprocket

  13. Place track block (D) in sprocket (4) to block forward left travel.

  14. Slowly move the left travel control lever to full FORWARD position.

  15. Check the pressure setting of the left forward travel crossover relief.

  16. Loosen the locknut of the left forward travel crossover relief valve. Turn adjustment screw of the left forward travel crossover relief valve until the pressure reading at pressure tap (1) is 37500 ± 500 kPa (5440 ± 72.5 psi).

    Note: Turn the adjustment screw clockwise to increase the pressure. Turn the adjustment screw counterclockwise to decrease the pressure.

    Note: To prevent over setting, the adjustment should be stopped immediately after the pressure becomes within specification.

  17. Remove track block (D) from sprocket (4).

  18. Place track block (D) in sprocket to block reverse left travel.

  19. Slowly move the left travel control lever to full REVERSE position.

  20. Check the pressure setting of the left reverse travel crossover relief.

  21. Loosen the locknut of the left reverse travel crossover relief valve. Turn adjustment screw of the left reverse travel crossover relief valve until the pressure reading at pressure tap (1) is 37500 ± 500 kPa (5440 ± 72.5 psi).

    Note: Turn the adjustment screw clockwise to increase the pressure. Turn the adjustment screw counterclockwise to decrease the pressure.

    Note: To prevent over setting, the adjustment should be stopped immediately after the pressure becomes within specification.

  22. To adjust the crossover relief valves on the right travel motor, repeat Step 13 through Step 21 for the right travel motor.

  23. Return the main relief valve pressure to the specified setting after crossover relief valve pressure setting is attained. Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".

Adjustment Procedure



Illustration 8g03328200
Crossover relief valve
(A) Adjustment screw
(L) Locknut

  1. Loosen locknut and turn adjustment screw to increase or decrease pressure.

    Note: Turn the adjustment screw clockwise to increase pressure. Turn adjustment screw counterclockwise to decrease pressure.

    Note: Always make final pressure adjustments on the pressure rise.

  2. Tighten the locknut to specification once all adjustments are complete.

Information System:

926M, 930M and 938M Wheel Loaders Power Train Piston Motor (Hydrostatic) - Assemble - Rear Hydrostatic Piston Motor
926M, 930M and 938M Wheel Loaders Power Train Piston Motor (Hydrostatic) - Disassemble - Rear Hydrostatic Piston Motor
926M, 930M and 938M Wheel Loaders Power Train Piston Motor (Hydrostatic) - Assemble - Front Hydrostatic Piston Motor
926M, 930M and 938M Wheel Loaders Power Train Piston Motor (Hydrostatic) - Disassemble - Front Hydrostatic Piston Motor
Retrofitting Boom Lowering Control Valve/Stick Lowering Control Valve on 345D/349D/349D2 Excavators {5051, 5057, 5059, 5456, 5458}
336D 2L and 340D 2L Excavators Machine Systems Pressure Reducing Valve (Implement and Swing Priority) - Remove and Install
538 Forest Machine Machine Systems Travel Motor - Test - Measurement of Case Drain Oil
308E2 CR, 308E2 SR Mini Hydraulic Excavator Diagnostic Trouble Codes
336D 2L and 340D 2L Excavators Machine Systems Gear Pump (Pilot) - Remove and Install
725C, 725C2, 730C, 730C2 and 730C, 730C2 EJECTOR Articulated Truck Systems Final Drive and Wheel
538 Forest Machine Machine Systems Relief Valve (Swing) - Test and Adjust
325F Excavator Engine Supplement Diesel Exhaust Fluid Pump - Remove and Install
Counterbalance Valves Are Now Used on Certain Hydraulic Excavator Forestry Grapples {5362, 5457, 5555, 6307}
336D2/336D2 GC Excavator Engine Supplement Turbocharger - Remove and Install
725C, 725C2, 730C, 730C2 and 730C, 730C2 EJECTOR Articulated Truck Systems Gear Motor (Hydraulic Fan)
336D 2L and 340D 2L Excavators Machine Systems Hydraulic Tank - Remove and Install
538 Forest Machine Machine Systems Process for Setting Up the Work Tool
325F Excavator Machine Systems Final Drive - Disassemble
325F Excavator Machine Systems Final Drive - Assemble
336D 2L and 340D 2L Excavators Machine Systems Pilot Valve (Joystick) - Remove and Install
303.5E2 CR Mini Hydraulic Excavator Machine ECM Diagnostic Trouble Codes
Installation Procedure for the Hydraulic Hand Control Gp (Universal) {5063}
303.5E2 CR Mini Hydraulic Excavator Machine ECM Event Codes
303.5E2 CR Mini Hydraulic Excavator Machine ECM General Information