Hydraulic Pressure in P/S Circuit Check
- 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.
Special Tool
- 09915-77411
- 09915-77420
- 09945-36010
- Check each connection for fluid leakage and bleed air. Refer to AIR BLEEDING PROCEDURE .
- With engine idling, turn steering wheel and warm up engine till temperature of fluid in tank rises to 50 - 60°C (122 - 140°F).
- Check back pressure by measuring hydraulic pressure with engine idling and hands off steering wheel.
Back pressure
Lower than 1000 kPa (10 kg/cm 2 , 142 psi)
When back pressure is higher than specified values, check control valve and piping for clogging.
- Check relief pressure.
- Increase engine speed to about 1500 r/min. (RPM). Close gauge valve (2) gradually while watching pressure increase indicated by gauge and take reading of relief pressure (maximum hydraulic pressure).
Relief pressure
8200 - 8900 kPa (82 - 89 kg/cm 2 , 1166 - 1265 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 (4) or setting of relief valve spring.CAUTION: Be sure not to close gauge valve for longer than 10 seconds.
- Next, open gauge valve (2) fully and increase engine speed to about 1500 r/min. Then turn steering wheel to the left or right fully and take reading of relief pressure.
Relief pressure
8200 - 8900 kPa (82 - 89 kg/cm 2 , 1166 - 1265 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 (5). Replace gear box.CAUTION: Be sure not to hold steering wheel at fully turned position for longer than 10 seconds.
- Increase engine speed to about 1500 r/min. (RPM). Close gauge valve (2) gradually while watching pressure increase indicated by gauge and take reading of relief pressure (maximum hydraulic pressure).