In Chassis Test and Adjust Procedure
| Required Tools | ||
|---|---|---|
| Part Number | Description | Required Amount |
| 198-4240 | Digital Pressure Indicator | 1 |
| 2J-5608 | Cover | 1 |
| 4J-0527 | O-Ring Seal | 1 |
Note: Make sure that the filters and the screens are clean before you test any pressures. Make sure that the oil is at operating temperature before you perform this test.
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| Illustration 1 | g01273372 |
(1) Pressure tap on the pump | |
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| Illustration 2 | g01273373 |
(2) Tube assembly (3) Brake oil cooler relief valve | |
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| Illustration 3 | g00532762 |
Section view of brake oil cooler relief valve (3) (3) Brake oil cooler relief valve (4) Shims | |
- Connect 198-4240 Digital Pressure Indicator to pressure tap (1) .
- Start the engine. Run the engine at low idle.
- Raise the dump body.
- Move the control lever for the hoist control to the Float.
- When the display indicates the dump body has entered SNUB, look at the pressure gauge. The pressure reading should be less than 1725 kPa (250 psi).
Note: The Snub position can be read on the ET screen, the Messenger screen, or the Advisor screen.
Note: The pressure reading was the result of bench testing the relief valve at a flow rate of 38 L/min (10 US gpm). The flow rate of the pump at low idle is 167 L/min (44 US gpm). The resulting pressure may be higher than the value that is provided.
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| Illustration 4 | g01566077 |
Typical | |
- The pressure can be lowered in ET by using the "hoist Lower adjustment". See Special Instruction, REHS5053, "777G Off-Highway Truck Assembly", "Adjustment for Hoist Lower Value".
Note: Special Instruction, REHS5053, "777G Off-Highway Truck Assembly", "Adjustment for Hoist Lower Value" is not complete yet.
- Stop the engine.
- Remove the test equipment.
Bench Test and Adjustment
| Shims For Adjusting The Relief Valve Pressure Setting | ||
| Part Number | Thickness | Pressure Change |
| 8B-4624 | 0.81 mm (0.032 inch) |
30 kPa (4 psi) |
Problem: The pressure is less than 586 ± 14 kPa (85 ± 2 psi).
Probable Cause
- Brake oil cooler relief valve (3) is stuck open.
- Brake oil cooler relief valve (3) is set too low. Add shims (4). Refer to Table 2.
Problem: The pressure is greater than 586 ± 14 kPa (85 ± 2 psi).
Probable Cause
- Brake oil cooler relief valve (3) is set too high. Remove shims (4). Refer to Table 2.