6C
Hydraulic Pressure in P/S Circuit Check
1) Clean where pipe is connected thoroughly, then disconnect high pressure hose from high pressure pipe connector and connect oil pressure gauge (special tool) as shown.
Special Tool
(A) : 09915–77410 (M13 engine model)
(A) : 09915–77412 (K9K engine model)
(B) : 09915–77420
[A]: M13 engine model 3. Washer
[B]: K9K engine model 4. Union bolt
1. To gear box 5. Pressure hose
2. Attachment    
2) Bleed air.
3) With engine running at idling speed, keep turning steering wheel to the right and left till fluid in P/S fluid reservoir is warmed to 50 – 60 °C (122 – 140 °F).
[A]: M13 engine model 1. Thermometer
[B]: K9K engine model    
4) Back pressure check
With engine running at idling speed and hands off from steering wheel, check hydraulic pressure.
If back pressure exceeds 980 kPa (10 kg/cm², 142 psi), check control valve and pipes for obstruction.
Back pressure
M13 engine model: 980 kPa (10 kg/cm², 142 psi)
K9K engine model: 350 kPa (3.5 kg/cm², 50 psi)
1. P/S fluid reservoir 5. Low pressure side
2. P/S pump 6. High pressure side
3. Steering gear box 7. Valve (open)
4. Oil pump pressure gauge    
5) Relief pressure check.
CAUTION:
Be sure not to keep gauge valve closed for longer than 10 seconds.
Never keep steering wheel turned fully for longer than 10 seconds.
a) Increase engine speed to about 1,500 – 1,600 rpm.
Close valve (6) gradually while watching pressure increase indicated on gauge (4) and take reading of relief pressure (maximum hydraulic pressure).
If relief pressure is not as specified, replace P/S pump.
Relief pressure
M13 engine model: 6,400 – 8,400 kPa (65 – 85 kg/cm², 925 – 1208 psi)
K9K engine model: 8,400 – 9,100 kPa (85 – 92 kg/cm², 1208 – 1308 psi)
1. P/S fluid reservoir 3. Steering gear box
2. P/S pump 5. High pressure side
b) Next, open gauge valve (6) fully and increase engine speed to about 1,500 – 1,600 r/min. Then turn steering wheel to the left or right fully and take reading of relief pressure.
If lower than 6,400 kPa (65 kg/cm², 1280 psi), failure in steering gear. (M13 engine model)
If lower than 8,400 kPa (85 kg/cm², 1208 psi), failure in steering gear. (K9K engine model)
Relief pressure
M13 engine model: 6,400 – 8,400 kPa (65 – 85 kg/cm², 925 – 1208 psi)
K9K engine model: 8,400 – 9,100 kPa (85 – 92 kg/cm², 1208– 1308 psi)
1. P/S fluid reservoir 4. Oil pressure gauge
2. P/S pump 5. High pressure gauge
3. Steering gear box