Power Steering System Test
- Check reservoir level and examine power steering units and connections for leaks. All leaks must be corrected before proceeding with test. Check drive belt for tension and condition. Release bellows from rack ends and check for fluid leakage. Install suitable test gauge (JD10) and test valve (10-2) to pump outlet line as shown in illustration. Ensure all air is exhausted from circuit, oil level in reservoir is correct, and oil is at normal operating temperature.
- With test valve open and engine running, gently turn steering wheel to left and right lock while observing pressure gauge. A pressure of 750-850 psi (52.73-59.76 kg/sq. cm) should be recorded in both cases. If pressure is not within specifications, or a pressure imbalance exists, a fault exists in system.
- Close test valve for a period not exceeding five seconds. If gauge fails to read 750-850 psi (52.73-59.76 kg/sq. cm), pump is inefficient and pump relief/flow valve should be examined and replaced as necessary. Repeat this test after replacing relief/flow valve and bleeding system. If pump still falls below specifications, repair or replace pump.
- Remove rack cylinder pipes from rack control valve and seal ports using suitable plugs. With engine idling, turn steering gently to left and right, observing gauge reading.CAUTION: Do not hold wheel in either direction for periods exceeding five seconds.
Check that 750-850 psi (52.73-59.76 kg/sq. cm) is obtained in both directions. If pressure is not to specifications, rack control valve is defective. If pressure is within specifications, fault lies in rack assembly.