"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 | |
|
Reverse | |
||
Right Travel | Forward | |
|
Reverse | |
The crossover relief valves are on the travel counterbalance valves. The following procedure will determine if the crossover relief valves are out of adjustment.
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Illustration 1 | g01623868 |
Tooling group "B" 198-4240 Digital Pressure Indicator Gp |
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Illustration 2 | g03261789 |
(D) |
Tool | Item | Part Number | Description | Qty |
---|---|---|---|---|
B | 198-4240 | Digital Pressure Indicator Gp | ||
B1 | 198-4234 | Indicator | 1 | |
B2 | 198-4239 | Pressure Sensor |
2 | |
B3 | 198-4236 | Extension Cable | 2 | |
D | 418-3611 | Track Block | 1 |
- Position the machine on level ground.
- Stop the engine.
- Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
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Illustration 3 g03861334 Pump compartment
(1) Pressure tap (delivery pressure for drive pump)
(2) Pressure tap (delivery pressure for idler pump)
(3) Pressure tap (power shift pressure) - 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. - 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. - Connect a
3445 kPa (500 psi) pressure sensor to pressure tap (3). Use this pressure sensor to monitor the power shift pressure.
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.
Function | Temporary Main Relief Setting |
---|---|
Left Travel Forward and Reverse | |
Right Travel Forward and Reverse |
Relief Valve | Pressure Change With One Turn Of Adjustment Screw |
---|---|
Main relief valve | |
Crossover relief valves | |
Note: Pressure values in Table 4 are approximate values. Use a pressure gauge for adjustment.
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Illustration 4 | g02240859 |
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 |
- Start the engine.
- Place the hydraulic activation control lever in the UNLOCKED position.
- Increase the hydraulic oil temperature to
55° ± 5°C (131° ± 9°F) . - 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.
- Move the joystick for the stick until the stick is at the full STICK OUT position (full retraction of stick cylinder).
- 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) . - Return the joystick to the NEUTRAL position.
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Illustration 5 g02102305 Main relief valve (standard)
(A) Adjustment screw
(L) LocknutShow/hide tableIllustration 6 g02102306 Main relief valve (heavy lift)
(A) Adjustment screw
(L) Locknut - 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.
- 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) . - Enter the service mode.
- Input the password "9992".
- Select "Override Parameters".
- Override "Power Shift Pressure" to
1070 ± 50 kPa (155 ± 7 psi) . Confirm the power shift pressure setting at pressure tap (3). - Set the engine speed dial to position "1".
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Illustration 7 g03261818 Sprocket (left travel)
(D) Track block
(4) Sprocket - Place track block (D) in sprocket (4) to block forward left travel.
- Slowly move the left travel control lever to full FORWARD position.
- Check the pressure setting of the left forward travel crossover relief.
- 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.
- Remove track block (D) from sprocket (4).
- Place track block (D) in sprocket to block reverse left travel.
- Slowly move the left travel control lever to full REVERSE position.
- Check the pressure setting of the left reverse travel crossover relief.
- 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.
- To adjust the crossover relief valves on the right travel motor, repeat Step 13 through Step 21 for the right travel motor.
- 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".
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Illustration 8 | g03328200 |
Crossover relief valve (A) Adjustment screw (L) Locknut |
- 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.
- Tighten the locknut to specification once all adjustments are complete.