Hydraulic Power Steering Symptom Troubleshooting

Find the symptom in the chart below, and do the related procedures in the order listed until you find the cause.

Symptom | Procedure(s) | Also check for:
--- | --- | ---
Hard steering | Troubleshoot the system. |

- Modified suspension
- Damaged suspension
- Tyre sizes, tyre varieties, and air pressure

Assist (excessively light steering at high speed) | Check the rack guide adjustment. | Front wheel alignment
Shock or vibration when the steering wheel is turned to full lock | 1. 2. 3. 4. | Check the rack guide adjustment. Check the drive belt for slippage. Check the power steering pump fluid pressure. Overhaul the steering gearbox. |
Steering wheel will not return smoothly | 1. 2. 3. 4. | Check cylinder lines for deformation. Check upper and lower ball joints for binding. Check wheel alignment. Overhaul the steering gearbox. |
Uneven or rough steering | 1. 2. 3. 4. 5.
6.
Check the rack guide adjustment.
Check the drive belt.
Check low or erratic engine idle speed.
Check for air in the power steering system due to air entering inlet side of pump.
Check for low fluid level in the power steering reservoir due to possible leaks in system.
Overhaul the steering gearbox.
Steering wheel kicks back during wide turns | 1. 2. | Check the drive belt. Check the power steering pump fluid pressure. |
Humming noise from the power steering system | 1. 2. 3. 4. 5. | Check when the noise occurs:

- If the noise is heard 2−3 minutes after starting the engine in cold weather, this is normal.
- If the noise is heard when the wheel is turned with the vehicle stopped, this is normal due to the fluid pulsation.

Check for the high-pressure hose touching the subframe or body.
Check for automatic transmission converter noise.
Check for air bubbles in the power steering fluid, leak on inlet side of pump.
Check for particle contamination of fluid and restricted filter in the reservoir.
Pump pressure
Power steering rack rattle or chattering | 1. 2. 3. 4. | Check for loose steering components (tie-rod and ball joints). Tighten or replace as necessary. Check the steering column shaft for wobbling. If the steering column wobbles, replace the steering column assembly. Check the rack guide adjustment.
Check the power steering pump pulley:

- If the pulley is loose, tighten it.
- If the pump shaft is loose, replace the pump.

Hissing from the power steering system |

- Check the fluid level. If low, fill the reservoir to the proper level and check for leaks.
- Check the reservoir for leaks.
- Check for crushed inlet hose or loose hose clamp allowing air into the suction side of the system.
- Check the power steering pump shaft oil seal for leaks.

Air in the P/S fluid
Noise from the power steering pump |

- Compare the pump noise at normal operating temperature to another like vehicle (pump noise up to 2−3 minutes after starting the engine in cold weather is normal).
- Remove and inspect the pump for wear and damage.

- P/S pump pressure
- Air in the P/S fluid

Squeaking from the power steering pump | Check the drive belt. |
Fluid leaks from the steering gearbox |

- Fluid leaks from the top of the valve body unit: Overhaul the steering gearbox.
- Fluid leaks from the driver's side boot: Replace the valve oil seal on the pinion shaft.Replace the cylinder end seal.
- Fluid leaks from the passenger's side boot: Replace the cylinder end seal.
- Fluid leaks from pinion shaft near the lower steering joint bolt: Overhaul the valve body unit.
- Fluid leaks from the steering damping valve covers on the valve body unit: Replace the valve housing.

Fluid leaks from the power steering line |

- Fluid leaks from the cylinder line connections (flare nuts): Tighten the connection and retest.
- Fluid leaks from a damaged cylinder lines: Replace the cylinder line.
- Fluid leaks from the pump outlet hose or return line fitting on the valve body unit (flare nuts): Tighten the fitting and retest. If it still leaks, replace the hose, the line, or valve body unit as necessary.

Fluid leaks from the power steering pump |

- Fluid leaks from the front oil seal: Replace the front oil seal.
- Fluid leaks from the power steering pump housing: Replace the leaking O-rings or seals, and if necessary replace the power steering pump.

Fluid leaks from the power steering reservoir |

- Fluid leaks from around the reservoir cap: Fluid level is too high: Drain the reservoir to the proper level. Aerated fluid: Check for an air leak on the inlet side of pump.
- Fluid leaks from reservoir: Check for the reservoir for cracks and replace as necessary.

Fluid leaks from the power steering pump outlet hose (high-pressure) |

- Check the fitting for loose bolts. If the bolts are tight, replace the fitting O-ring.
- Fluid leaks at the swagged joint: Replace the outlet hose.

Fluid leaks from the power steering pump inlet hose (low-pressure) | Check the hose for damage, deterioration, or improper assembly. Replace or repair as necessary. |