Line Pressure Measurement
NOTE: Special tools: 2531, 50741. Check fluid level. Refer to "Checking Fluid". Testing and Inspection
2. Connect pressure gauge.
Pressure Gauge Attachment:
Attach pressure gauge 2531 to side window. Remove front plug on gearbox and install connector 5074. Connect tube to connector.
3. Start engine and allow to idle with gear selector in position N. Check idling speed.
4. Depress brake pedal. Place gear selector in position D and read line pressure.
Pressure At Idle Position D:
5. Move gear selector to position R and read line pressure.
Pressure At Idle Position R:
Deviations:
Line pressure too high
Is kickdown cable correctly adjusted? No: Adjust cable. Yes: Check valves as described below.
- Primary regulator valve. Rev engine. If pressure varies in proportion to engine speed, valve is stuck and normal pressure control is inoperable. Dismantle control system.
- Throttle valve. Idle engine with gear selector in position N. Operate throttle valve by hand (without moving throttle). If line pressure does not increase, throttle valve is sticking. Dismantle control system.
- Shift valves 1-2 and 2-3
- Cutback valve
Pressure correct but fails after a couple of seconds
Secondary regulator valve may be faulty or earlier type of valve may be fitted. Replace with later type.
No pressure (no rearward propulsion)
- Faulty or blocked primary regulator valve, shift valve 2-3 or rear brake B3 control valve. Clean and inspect.
- Faulty operation of accumulator piston C2.
- Undo center support unit mounting bolts and retorque.
Pressure Gauge Attachment:
Line pressure too low
- This may be due to sticky primary regulator or throttle valve. Check as described in operation above.
- If inspection reveals that valves are not sticking, low pressure may be due to faulty relief valve or oil pump. (In this case, pump will usually be noisy.) Alternately, oil strainer may be blocked.
- Low line pressure may also be due to a faulty accumulator piston.