Hydraulic Pressure Check

1. After cleaning joint of high pressure hose and P/S pump thoroughly, disconnect hose from pump and install special tool (oil pressure gauge, attachment and hose). Tighten each flare nut to specified torque.

CAUTION: Take care not to cause damage to A/C condenser during service operation, if equipped.

Special Tool (A): 09915-77410 (Oil pressure gauge) (B): 09915-77420
2. Check each connection for fluid leakage and bleed air. (Refer to Air Bleeding Procedure.)





3. With engine idling, turn steering wheel and warm up engine till temperature of fluid in tank rises to 50-60°C (122-140°F).





4. Check back pressure by measuring hydraulic pressure with engine idling and hands off steering wheel.

Back pressure: Lower than 1000 kPa (10 kg/cm2, 142 psi)

When back pressure is higher than specified values, check control valve and piping for clogging.





5. Check relief pressure
- Increase engine speed to about 1,500 r/min (rpm). Close gauge valve gradually while watching pressure increase indicated by gauge and take reading of relief pressure (maximum hydraulic pressure).

Relief pressure: 7200-8000 kPa (72-80 kg/cm2, 1024-1138 psi)

- When it is higher than specified values, possible cause is malfunction of relief valve.
- When it is lower than specified values, possible cause is either failure of P/S pump or settling of relief valve spring.

CAUTION: Be sure not to close gauge valve for longer than 10 seconds.





- Next, open gauge valve fully and increase engine speed to about 1,500 r/min (rpm). Then turn steering wheel to the left or right fully and take reading of relief pressure.

Relief pressure: 7200-8000 kPa (72-80 kg/cm2, 1024-1138 psi)

- When it is higher than specified values, possible cause is malfunction of relief valve.
- When it is lower than specified values, possible cause is failure in steering gear box. Replace gear box.

CAUTION: Be sure not to hold steering wheel at fully turned position for longer than 10 seconds.