| Tools Needed | Qty |
| 198-4240 Digital Pressure Indicator | 1 |
| 198-4238 Pressure Sensor | 1 |
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Personal injury or death can occur if personnel are trapped between the wheel and the frame. The steering system is hydraulically controlled and wheels can crush personnel during movement. Use caution when working between the wheels and the frame. If the wheels must be turned, ensure that all personnel are clear of the machine before any movement. |
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Note: Make sure that the steering disable valve is connected to the electrical system during the tests.
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| Illustration 1 | g01622615 |
(1) Steering piston pump (2) Pressure and flow compensator valve (3) Flow compensator valve (4) High pressure cutoff valve | |
Pressure and flow compensator valve (2) is mounted to the case of steering piston pump (1) . The steering piston pump (1) is mounted on the front side of the pump drive.
High Pressure Cutoff Valve
- Start the engine.
- Operate the engine at HI IDLE. Turn the steering wheel to the right or turn the steering wheel to the left until the steering cylinder stop is reached. Then, continue turning the steering wheel against the stop. Hold the steering wheel in this position for three seconds and then release the steering wheel. Continue this step until the oil in the steering system reaches at least 38 °C (100 °F) to 93 °C (200 °F).
- Check the steering system pressure by installing a 198-4240 Digital Pressure Indicator with the 198-4238 Pressure Sensor at pressure port (A) for the steering system. Refer to Illustration 2 in order to view the location of pressure port (A) .
Note: The pressure gauge needs to withstand the maximum pressure from the steering piston pump .
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| Illustration 2 | g01580034 |
(1) Steering check and relief valve group (2) Secondary system relief valve (3) Primary backup relief valve (4) Primary steering pressure switch (5) Pressure reducing valve (6) Secondary steering check valve (A) Pressure port | |
- Operate the engine at HI IDLE. Turn the wheels to the right or the left and keep turning the steering wheel. Check the pressure while you are turning the steering wheel. The pressure setting of the high pressure cutoff valve is 20850 kPa (3025 psi) to 22043 kPa (3197 psi).
- If the pressure needs to be adjusted, stop the engine.
- Remove cap (10) from setscrew (11) on high pressure cutoff valve (9) .
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| Illustration 3 | g01625598 |
(7) Pressure and flow compensator valve (8) Flow compensator valve (9) High pressure cutoff valve (10) Cap (11) Setscrew (12) Locknut | |
- Loosen locknut (12) of high pressure cutoff valve (9) .
- With an allen wrench, rotate setscrew (11) clockwise by 1/4 turn in order to raise the pressure. Rotate setscrew (11) counterclockwise by a 1/4 turn in order to lower the pressure. Each 1/4 turn of setscrew (11) changes the pressure approximately 1310 kPa (190 psi). Refer to Illustration 3in order to view the location of setscrew (11) .
- Repeat Steps 1 through 8 until the pressure setting is correct.
- If the pressure is low, and if the pressure does not increase with this method, use the following steps in order to troubleshoot the system.
- Check the setting of the primary backup relief valve (3) for the primary steering. Perform the Steering System Testing and Adjusting, "Relief Valve (Primary Steering Backup) - Test and Adjust". Refer to Illustration 3 in order to view the location of primary backup relief valve (3) .
- Check the setting of the pressure reducing valve (5) in order to be sure that the primary steering oil is not leaking to the steering hydraulic tank. Refer to Illustration 2 in order to view the location of pressure reducing valve (5) .
- Check the seat of the secondary steering check valve (6) in order to be sure that primary steering oil is not leaking into the secondary steering system. Refer to Illustration 2 in order to view the location of secondary steering check valve (6) .
- Check the seal of the primary steering pressure switch (4) in order to be sure that primary steering oil is not leaking from the steering check and relief valve group (1) . Refer to Illustration 2 in order to view the location of primary steering pressure switch (4) .
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Personal injury or death can result from improperly checking for a leak. Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. |
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- Remove the test equipment.
Flow Compensator Valve
- Start the engine.
- Operate the engine at HI IDLE. Turn the steering wheel until the wheels stop turning. Hold the steering wheel in this position for three seconds and then release the steering wheel. Continue this step until the oil in the steering system reaches at least 38 °C (100 °F) to 93 °C (200 °F). The steering system pressure will drop to low pressure standby when the steering wheel is not turned.
- Check the steering system pressure by installing a 198-4240 Digital Pressure Indicator with the 198-4238 Pressure Sensor at pressure port (A) for the steering system. Refer to Illustration 4 in order to view the location of pressure port (A) .
Note: The pressure gauge needs to withstand the maximum pressure from the steering piston pump .
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| Illustration 4 | g01580093 |
(1) Steering check and relief valve group (2) Secondary system relief valve (3) Primary backup relief valve (4) Primary steering pressure switch (5) Pressure reducing valve (6) Secondary steering check valve (A) Pressure port | |
- Operate the engine at HI IDLE. Check the pressure without turning the steering wheel. The pressure setting of the flow compensator valve (8) is 2000 kPa (290 psi) to 3600 kPa (522 psi).
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| Illustration 5 | g01625865 |
(7) Pressure and flow compensator valve (8) Flow compensator valve (9) High pressure cutoff valve (10) Cap (11) Setscrew (12) Locknut | |
- If the pressure needs to be adjusted, stop the engine.
- Remove cap (10) from setscrew (11) on flow compensator valve (8) .
- Loosen locknut (9) of flow compensator valve (5) .
- With an allen wrench, rotate setscrew (11) clockwise by 1/4 turn in order to raise the pressure. Rotate setscrew (11) counterclockwise by a 1/4 turn in order to lower the pressure. Each 1/4 turn of setscrew (11) changes the pressure approximately 414 kPa (60 psi). Refer to Illustration 5 in order to view the location of setscrew (11) .
- Repeat Steps 1 through 8 until the pressure setting is correct.
If the pressure cannot be adjusted, check flow compensator valve (8) . The spool may be sticking. Replace the entire pressure and flow compensator valve (7) if the spool or the bore is damaged. Refer to Illustration 5 in order to view the location of check flow compensator valve (8) .
- Remove the test equipment.