Power Steering Symptom Troubleshooting - Hard Steering

Hard Steering

1.Check the power assist.

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

YES - Go to 2.

NO - Power assist is OK.n

2.Connect the P/S pressure gauge to the pump.

3.Measure steady-state fluid pressure from the pump at idle.

Is the pressure 1,470 kPa (15 kgf/cm2, 213 psi) or less?

YES - Go to 4.

NO - Go to 8.

4.Measure the pump relief pressure at idle.

Is the pressure 7,850-8,550 kPa (80-87 kgf/cm2, 1,140-1,240 psi) or more?

YES - Go to 5.

NO - Go to 9.

5.With 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 6.

NO - Go to 11.

6.Measure the fluid pressure with both pressure gauge valves open, while turning the steering wheel fully to the left and fully to the right.

Is the pressure 7,850-8,550 kPa (80-87 kgf/cm2, 1,140-1,240 psi) or more?

YES - Go to 7.

NO - Faulty gearbox.n

7.Adjust the rack guide, and retest.

Is the steering OK?

YES - Repair is completed.n

NO - Faulty gearbox.n

8.Check the outlet and return hoses and lines between the pump and the gearbox for clogging and deformation.

Are the lines clogged or deformed?

YES - Repair or replace the lines.n

NO - Faulty valve body unit.n

9.Disassemble the pump.

10.Check the pressure control valve for smooth movement and leaks.

Is the pressure control valve OK?

YES - Faulty pump assembly.n

NO - Faulty pressure control valve.n

11.Check the cylinder lines for deformation.

Are any of the lines deformed?

YES - Replace the deformed line.n

NO - Go to 12.

12.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.n

NO - Faulty valve body unit.n