System Pressure Test

NOTE: If steering lacks power assistance:
- Check pressure of hydraulic pump before installing new components.
- Use fault diagnosis chart to assist in tracing faults.





PROCEDURE
1. A suitable hydraulic pressure gauge and test adapter is used to test power steering system.
- This gauge should be able to measure 140 kgs./cm 2, 2000 psi.
- The maximum power steering system pressure is 77 kgf/cm2, (1100 psi).
2. Some fault conditions of hydraulic pump may obtain pressures up to 105 kgf/cm2, 1250 psi.
- Pressure on gauge is same pressure being exerted upon steering wheel.
- When testing, turn steering wheel gradually while reading pressure gauge.
3. Check and maintain maximum fluid level of reservoir.
4. Examine power steering units and connections for leaks.
- All leaks must be rectified before attempting to test the system.
5. Check steering pump drive belt tension.
6. Assemble test equipment and install to vehicle, as shown in illustration.
7. Open tap of adapter.
8. Bleed system, take care not to overload pressure gauge.
9. With system in good condition, pressures should be:
A. Steering wheel held on full lock and engine running at 1,000 rpm, 70 to 77 kgf/cm2, (1000 to 2000 psi).
B. Steering wheel held on full lock and engine idling, 28 kgf/cm2, (400 psi).

NOTE: Checks should be carried out on both full lock positions.

CAUTION: Do not maintain this pressure for more than 30 seconds in any one minute to avoid overheating fluid and possibly damaging seals.

10. Release steering wheel and with engine idling.
- Pressure should read below 7 kgf/cm2, (100 psi).
11. If pressures differ to those given a fault exists.
12. To determine if fault is steering box or pump.
- Close adapter tap for a maximum five seconds.
13. If gauge does not register specified pressure, pump is faulty.
14. Install a new pump, bleed system and repeat test.
- If low pressure or a substantial imbalance exists, fault is in steering box valve and worm assembly.