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Personal injury can result from contact with hot hydraulic oil and from contact with hydraulic oil that is under high pressure. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. The hydraulic oil pressure must be released before any service on the hydraulic system is performed or serious personal injury could occur. Verify that all of the work tools have been completely lowered to the ground. Release the hydraulic oil pressure at the hydraulic tank through the breaker relief valve when the breaker relief valve is cool enough to touch with your bare hand. Verify that the hydraulic oil is cool before you begin to remove any hydraulic components or hydraulic lines. |
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| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids. Dispose of all fluids according to local regulations and mandates. |
Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any system pressure that may be present in the hydraulic system.
ReferenceFor the correct procedure to prepare the machine for this test, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
ReferenceFor the correct procedure to relieve any hydraulic oil pressure that may be present in the hydraulic system, refer to Testing and Adjusting, "System Pressure - Release" for the machine that is being serviced.
| Required Tools | ||
| Part Number | Description | Qty |
| 198-4240 | Digital Pressure Indicator | 1 |
| 177-7861 | Hose Assembly | 1 |
Preparation for Test
- Place the machine on level ground.
- Open the hood for the engine compartment.
 | |
| Illustration 1 | g01162081 |
The switch for the hood | |
 | |
| Illustration 2 | g01069398 |
- Shut off the engine.
- Disconnect the wire from the solenoid for the swing parking brake.
 | |
| Illustration 3 | g01070478 |
Remove the cover underneath the machine in order to access the pilot manifold. | |
 | |
| Illustration 4 | g01477614 |
The solenoid for the swing parking brake is located on the pilot manifold. | |
- Release all the system hydraulic pressure. For information on the correct procedure to release pressure, refer to the reference at the beginning of this test.
- A temporary setting of the main relief valve on the implement valve is required before you perform the test procedure.
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| Illustration 5 | g01486734 |
(1) Pressure tap for the implement pump (2) Implement pump | |
 | |
| Illustration 6 | g01484333 |
Implement control valve (3) Signal limiter valve CLOCKWISE (4) Signal limiter valve COUNTERCLOCKWISE (5) Main relief valve for implement valve | |
- Attach the 198-4240 Digital Pressure Indicator to pressure tap (1) with the hose assembly.
- Start the engine. Move the engine speed dial to 1400 rpm. Raise the boom to the STALLED position.
- Loosen the locknut on main relief valve (5) of the implement valve. Turn the adjustment screw clockwise until the pressure gauge reads 38600 kPa (5600 psi). This will allow the line relief valves of the swing motor to actuate before the main relief valve.
- Tighten the locknut on main relief valve (5) .
- Shut off the engine
- Turn the signal limiter valves (3) and (4) until the signal limiter valves bottom out on the swing control valve.
Test
- Start the engine.
- Increase the hydraulic oil temperature to 55° ± 5°C (130° ± 10°F).
- Move the engine speed dial to high idle.
- Move the hydraulic lockout control to the UNLOCKED position.
 | |
| Illustration 7 | g01162712 |
Hydraulic Lockout Control | |
- Slowly move the left joystick control for a full RIGHT swing operation. Read the pressure gauge. Slowly move the left joystick control for a full LEFT swing operation. Read the pressure gauge. The pressure should be 37200 ± 300 kPa (5400 ± 50 psi) in both directions.
- Move the left joystick control to the HOLD position.
- If the pressure is correct proceed to Step 18. If the pressure for the RIGHT swing is incorrect proceed to Step 8 in order to adjust the relief valve. If the pressure for the LEFT swing is incorrect proceed to Step 12 in order to adjust the relief valve.
- Loosen locknut (10) on relief valve (6). Slowly move the left joystick control for a full RIGHT swing operation.
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| Illustration 8 | g01478833 |
(6) Relief valve (swing right) (7) Swing motor (8) Relief valve (swing left) | |
 | |
| Illustration 9 | g01478872 |
- Turn adjustment screw (9) clockwise in order to increase the pressure. Turn adjustment screw (9) counterclockwise in order to decrease the pressure.
- Adjust the pressure to 37200 ± 300 kPa (5400 ± 50 psi). Move the left joystick control to the HOLD position.
Note: Always make final pressure adjustment on the pressure rise.
- Tighten locknut (10) .
- Loosen locknut (10) on relief valve (8). Slowly move the left joystick control for a full LEFT swing operation.
- Turn adjustment screw (9) clockwise in order to increase the pressure. Turn adjustment screw (9) counterclockwise in order to decrease the pressure.
- Adjust the pressure to 37200 ± 300 kPa (5400 ± 50 psi). Move the left joystick control to the HOLD position.
Note: Always make final pressure adjustment on the pressure rise.
- Tighten locknut (10) .
- Readjust the signal limiter valves in the swing control valve to 35500 ± 300 kPa (5150 ± 50 psi).
- Readjust the main relief valve to 35500 ± 300 kPa (5150 ± 50 psi).
- Move the engine speed dial to low idle. Shut off the engine.
- Release all the system hydraulic pressure.
- Remove the test equipment.
- Reconnect the wire to the solenoid for the swing parking brake.