Hydraulic Pressure In P/S Circuit Check

Hydraulic Pressure in P/S Circuit 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).

Special Tool
(A): 09915-77412
(B): 09915-77420
(C): 09945-36010








2) Check each connection for fluid leakage and bleed air.
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.
When back pressure is higher than specified values, check control valve and piping for clogging.

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








5) Check relief pressure.
^ With engine idling, close gauge valve (2) gradually while watching pressure increase indicated by gauge and take reading of relief pressure (maximum hydraulic pressure).
^ If it is higher than specified values, possible cause is malfunction of relief valve.
^ If it is lower than specified values, possible cause is either failure of P/S pump (4) or relief valve.

Relief pressure
10100 - 10600 kPa (103 - 108 kgf/cm2, 1465 - 1537 psi)

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








^ Open gauge valve (2) fully with engine idling. Then turn steering wheel to the left or right fully and take reading of relief pressure.
^ If it is higher than specified values, possible cause is malfunction of relief valve.
^ If it is lower than specified values, possible cause is failure in steering gear case (5).
Replace gear case.

Relief pressure
10100 - 10600 kPa (103 - 108 kgf/cm2, 1465 - 1537 psi)

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