Symptom Troubleshooting

Symptom Troubleshooting: Hard steering

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. Power Assist Check

Is the initial turning load more than 29 N (3.0 kgf, 6.6 lbf) ?
YES - Go to step 2.

NO - Power assist is OK at this time. Compare to a known-good vehicle.


2. Connect the P/S joint adapter (pump), P/S joint adapter (hose), and P/S pressure gauge T/N 07406-0010001 Power Steering Pump Pressure Test With T/N 07406-0010001, T/N 07406-001000A or T/N 07406-001A101 Power Steering Pump Pressure Test With T/N 07406-001000A or T/N 07406-001A101 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 step 4.

NO - Go to step 8.


4. Measure the pump relief pressure at idle.

Is the pressure 8,140-8,830 kPa (83-90 kgf/cm2, 1,180-1,280 psi) or more?
YES - Go to step 5.

NO - Go to step 9.


5. 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 6.

NO - Go to step 11.


6. 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 8,140-8,830 kPa (83-90 kgf/cm2, 1,180-1,280 psi) or more in both directions?
YES - Go to step 7.

NO - Faulty steering gearbox. Overhaul the steering gearbox. Overhaul


7. Adjust the rack guide, Adjustments and retest.

Is the steering OK?
YES - Repair is completed.

NO - Faulty steering gearbox. Overhaul the steering gearbox. Overhaul


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

Are the lines clogged or deformed?
YES - Replace the lines.

NO - Faulty valve body unit. Overhaul the steering gearbox. Overhaul


9. Disassemble the pump. Overhaul

10. Check the flow control valve for smooth movement and leaks. Overhaul

Is the flow control valve OK?
YES - Faulty pump assembly. Replace the pump assembly. Removal and Replacement

NO - Faulty flow control valve. Replace the flow control valve. Overhaul


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

Are any of the line(s) deformed?
YES - Replace the deformed line(s).

NO - Go to step 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 preload.

NO - Faulty valve body unit. Replace the valve body unit.