The following procedure is used to adjust the maximum pressure to the steering cylinders when the proportional steering switch is used. The maximum pressure is controlled by two signal limiter valves in the implement control valve. One signal limiter valve controls the maximum pressure for a left turn. The other signal limiter valve controls the maximum pressure for a right turn.
Before testing or adjusting the signal limiter valves, ensure that the standby pressure and the high pressure cutoff are adjusted correctly. In order to accurately adjust the steering cylinder pressure, the valve spool for the steering system must be moved fully from the HOLD position. The proportional solenoid for the valve spool must be fully activated. To ensure that the solenoid is fully activated, adjust the maximum current from the proportional steering switch above 680 mA.
Reference: For more information on the maximum current setting, refer to Testing and Adjusting, "Joystick Control Preferences - Adjust" for the machine that is being serviced.
Reference: For more information on the standby pressure, refer to Testing and Adjusting, "Implement Pump Standby Pressure - Test and Adjust" for the machine that is being serviced.
Reference: For more information on the high pressure cutoff, refer to Testing and Adjusting, "Implement Pump High Pressure Cutoff - Test and Adjust" for the machine that is being serviced.
Reference: For more information on the steering metering unit that is used in the steering system, refer to Testing and Adjusting, "Relief Valve (Steering Signal) - Test and Adjust" for the machine that is being serviced.
| Required Tools | ||
| Part Number | Description | Quantity |
| 198-4240 | Digital Pressure Indicator Group | 1 |
| 161-8958 | Wrench | 1 |
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Personal injury or death can result from escaping fluid under pressure. Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause 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. Always use a board or cardboard when checking for a leak. |
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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, "AVSpare Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on AVSpare products. Dispose of all fluids according to local regulations and mandates. |
- Ensure that the hydraulic oil in the system is at normal operating temperature. Park the machine on a level surface.
- Place the operating mode switch in the ROADING MODE position.
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| Illustration 1 | g00800981 |
Operating Mode Switch on the Right Hand Control Unit | |
- Place the parking brake switch in the ON position. The ladder will lower. Ensure that all personnel are clear of the ladder before you lower the ladder.
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| Illustration 2 | g00919915 |
Parking Brake Switch | |
- Stop the engine.
- Block the wheels.
- Install the steering frame lock.
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| Illustration 3 | g00913309 |
- Move the cover off the implement control valve.
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| Illustration 4 | g00914499 |
Location of the Implement Control Valve | |
- Install the 198-4240 Digital Pressure Indicator Group on pressure tap (1).
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| Illustration 5 | g00947790 |
End View of the Implement Control Valve (1) Pressure tap for piston pump (implement) signal pressure. (2) Pressure tap for piston pump (implement) supply pressure. | |
- Start the engine. Place the operating mode switch in the WORKING MODE position. Increase the engine speed to 1500 rpm.
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| Illustration 6 | g00800981 |
Operating Mode Switch on the Right Hand Control Unit | |
- Perform step 11 in order to adjust the pressure for a left turn. Perform step 12 in order to adjust the pressure for a right turn.
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| Illustration 7 | g00659806 |
Implement Control Valve (3) Steering section. (4) Signal limiter valve (LEFT TURN). (5) Signal limiter valve (RIGHT TURN). | |
- Left Turn:
- Move the steering activation switch to the ON position.
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Illustration 8 g00920175
Steering Activation Switch
- Move the proportional steering switch fully to the LEFT TURN position. The steering frame lock will prevent the machine from turning. The pressure gauge should indicate 18500 kPa (2675 psi).
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Illustration 9 g00920163
Proportional Steering Switch
- If the pressure setting is not correct, release the proportional steering switch. Remove the acorn nut from signal limiter valve (4) with a 13 mm wrench. Remove the grommet. Loosen the locknut for the adjustment screw with the 161-8958 Wrench .
- Turn the adjustment screw with an allen wrench. Tighten the locknut. Perform Step 11.b again in order to check the new pressure setting.
- Install the grommet and the acorn nut after the correct pressure setting is achieved.
- Right Turn:
- Move the steering activation switch to the ON position.
Show/hide table Illustration 10 g00920175
Steering Activation Switch
- Move the proportional steering switch fully to the RIGHT TURN position. The steering frame lock will prevent the machine from turning. The pressure gauge should indicate 18500 kPa (2675 psi).
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Illustration 11 g00920178
Proportional Steering Switch
- If the pressure setting is not correct, release the proportional steering switch. Remove the acorn nut from signal limiter valve (5) with a 13 mm wrench. Remove the grommet. Loosen the locknut for the adjustment screw with the 161-8958 Wrench .
- Turn the adjustment screw with an allen wrench. Tighten the locknut. Perform Step 12.b again in order to check the new pressure setting.
- Install the grommet and the acorn nut after the correct pressure setting is achieved.
- Remove the pressure gauge.