Hydraulic Power Steering Symptom Troubleshooting

Hydraulic Power Steering Symptom Troubleshooting

Hard Steering

NOTE:

- Compare to a known-good vehicle that is the same trim level.
- Check for suspension damage.
- Check the steering alignment.
- Check the tire condition and pressure.

1. Check the power assist.

Is the initial turning load more than 34 N (3.5 kgf, 7.7 lbf) ?

YES -

Do the pump pressure test with T/N 07406-0010001 Hydraulic Power Steering Pump Pressure Test With T/N 07406-0010001, T/N 07406-001000A or T/N 07406-001A101 Hydraulic Power Steering Pump Pressure Test With T/N 07406-001000A Or T/N 07406-001A101. If the test are OK, Go to step 2.

NO -

Power assist is OK. Compare to a known-good vehicle.�

2. Using a spring scale, measure the power assist in both directions, to the left and to the right.

Are the two measurements within 5.0 N (0.51 kgf, 1.12 lbf) of each other?

YES -

Go to step 3.

NO -

Go to step 5.

3. Measure the fluid pressure with both pressure gauge valves open (if so equipped), while turning the steering wheel fully to the left and fully to the right.

Is the pressure 7,355-8,041 kPa (75-82 kgf/cm2, 1,067-1,166 psi) or more?

YES -

Go to step 4.

NO -

Faulty steering gearbox. Overhaul the steering gearbox. Steering Gear�

4. Adjust the rack guide Adjustments, and retest.

Is the steering OK?

YES -

Repair is completed.�

NO -

Faulty steering gearbox. Overhaul the steering gearbox. Steering Gear�

5. Check the cylinder lines for deformation Service and Repair.

Are the lines clogged or deformed?

YES -

Repair or replace the line(s).�

NO -

Go to step 6.

6. Check for a bent rack shaft or misadjusted rack guide (too tight).

Is the rack shaft bent or the rack guide adjusted too tight?

YES -

Replace the rack shaft, or readjust the rack guide preload.�

NO -

Faulty valve body unit. Replace the valve body unit. Steering Gear�