Diagnostic Procedure

DIAGNOSTIC PROCEDURE



The following test may he carried out without removing any components from the car Before commencing work fluid should be checked for correct level and freedom from froth

Pump blow off pressure
- Fit pressure gauge reading to 100 kgf/cm2 (1500 psi) in pressure line from pump.
- Start engine and allow to run at idling speed.
- Turn steering to full lock and continue to increase steering effort until pressure recorded on gauge ceases to rise.
- Check that recorded pressure lies between 77.5 kgf/cm2 and 84,4 kgf/cm2 (1100 and 1200 psi).

NOTE: If pressure is below 77,5 kgf/cm (1000 psi) at idle, but rises to correct figure with increased engine speed the reason is a defective control valve in pump, or excessive internal leakage in rack and pinion unit. Carry out following test to establish location.

Steering Pressure Testing:

- Fit tap JD 102 between pump and pressure gauge arranging connections as shown, so that pressure gauge is at all times connected to pump, but rack unit can be isolated from it.
- With tap OPEN, start engine and allow to run at idling speed.
- Turn steering to full lock.
- Check that gauge reading exceeds 77,5 kgf/cm2 (1100 psi).
- If pressure does not reach this figure, CLOSE TAP AT ONCE, noting gauge reading as tap reaches 'OFF position.

CAUTION: Tap must not remain closed more than 5 seconds when engine is running.

- If reading of pressure gauge increases to at least 77,5 kgf/cm2 (1100 psi) when tap is turned off, leaks are confined to steering unit, which must be overhauled.
- If pressure reading exceeds 84,4 kgf/cm2 (1200 psi) remove pump discharge port, withdraw valve assembly located behind it, and inspect a small hemispherical gauze filter carried at its inner extremity, which may be blocked. Clean filter by compressed air or other means, and replace valve and discharge port.