Measurement of the hydraulic power steering operating pressure

Power steering oil pressure inspection is performed to inspect whether the power steering oil pump and power steering unit function properly.
Power steering system inspection is performed to specify the oil pressure circuit failure.

1. Preparation

Inspect the following and repair or refill as necessary before performing the power steering oil pressure inspection.

1) Bleed air from the power steering oil line.

Refer to "6.Steering 6B.Power Assisted System power steering fluid replacement".

2) Inspect the power steering oil pump drive gear.

2. Oil pressure inspection

1) Stop the engine.

2) Disconnect the pressure hose from the power steering oil pump.

3) Referring to the following diagram, install the special tool to the power steering oil line.

4JJ3 engine models

SST: 5-8840-0135-0 - power steering tester

SST: 5-8840-2297-0 - power steering tester adapter

Legend

RZ4E engine models

SST: 5-8840-0162-2 - power steering oil pressure gauge

SST: 5-8840-3260-0 - power steering tester adapter

Legend

4) Open the shut-off valve of the special tool.

5) Replenish the reservoir tank with the power steering fluid.

6) Start the engine.

If the engine is run for 5 seconds or more while the shut-off valve fully is closed, the inside of the power steering oil pump may be damaged.

7) Turn the steering wheel to full lock position and stop the engine.

8) Inspect for power steering oil line leakage using a tester.

9) Bleed air from the power steering oil line.

Refer to "6.Steering 6B.Power Assisted System power steering fluid replacement".

10) Start the engine.

11) After the engine is warmed up, raise the engine speed to 1,500 rpm.

12) Fully close the shut-off valve of the special tool and record the maximum pressure indicated on the pressure gauge.

If the measured maximum pressure is within the standard range, the power steering oil pump is functioning properly.
If the measured maximum pressure is more than or equal to the standard value, the power steering oil pump relief valve may be malfunctioning.
If the measured maximum pressure is less than or equal to the standard value, the power steering oil pump relief valve or rotor may be malfunctioning.

Standard: 9,800 to 10,300 kPa { 100 to 105 kgf/cm2 / 1,421 to 1,494 psi }

3. System inspection

1) Open the shut-off valve.

2) Record the maximum pressure indicated on a pressure gauge while turning the steering wheel to the leftmost position.

3) Record the maximum pressure indicated on a pressure gauge while turning the steering wheel to the rightmost position.

4) Compare the maximum pressure at the shut-off valve while fully closed with the maximum pressure at the shut-off valve while open and when the steering wheel is turned to the rightmost and leftmost positions.

As a result of the comparison, if the maximum pressure during the shut-off valve open and the steering wheel turned to the rightmost and leftmost positions is less than the maximum pressure during the shut-off valve fully closed, fluid leakage may have occurred within the power steering system.

5) Stop the engine.

6) Remove the special tool and bleed the air from the power steering oil line.

Refer to "6.Steering 6B.Power Assisted System power steering fluid replacement".