Initial Inspection and Diagnostic Overview
STEERING SYSTEM
Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical damage.
Visual Inspection Chart
3. Inspect the power steering fluid for the following conditions:
- Aeration or foam: Purge the power steering system. See Power Steering System Filling.
- Overheating or contamination: Flush the power steering system. See Power Steering System Flushing.
4.
NOTE:It may be necessary to add power steering fluid to achieve the correct level.Check the fluid level and clean the power steering components.
With the ignition OFF:
- check the power steering fluid level and add fluid as necessary.
- wipe off any visible signs of fluid or residue build up.
- Wipe off the power steering pump, power steering pressure hose, power steering return hose, power steering fluid cooler, hose assembly and steering gear.
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CAUTION:Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump may occur.Start the engine and turn the steering wheel from stop-to-stop several times.
5. Visually inspect the power steering hydraulic line/hose connections for leaks.
- If a leak is detected at a power steering pressure or return hose, install a new hose. See Description and Operation.
- If a leak is detected between a fitting nut, seal the fitting nut using a Teflon(R) joint seal.
- If a leak is detected at a threaded fitting or clamp plate joint, tighten to specification. If the leak is still evident, visually inspect the O-rings or Teflon(R) seals. Install new as necessary. See Description and Operation.
- If a leak is detected at the power steering reservoir, install a new reservoir. See - Service and Repair.
- If a leak is detected at a constant tension spring clamp, verify that the hose is not damaged and is fully installed on the hose fitting. Make sure that the constant tension spring clamp is correctly positioned. If the leak remains, install a new constant tension spring clamp.
- If a leak is detected at a screw clamp joint, verify that the hose is fully installed on the hose fitting before tightening the screw clamp. If the leak remains, install a new screw clamp. See Description and Operation.
- If a leak is detected at the power steering pressure switch, install a new switch.
6. Visually inspect the power steering components for leaks.
- If a leak is detected in the power steering pressure line or return hose, install a new hose.
- If a leak is detected at the power steering pump, install a new power steering pump. See - Power Steering Pump, or see - Power Steering Pump.
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NOTE:On vehicles with rack-and-pinion steering gear, it may be necessary to remove the bellows boot clamp from the steering gear bellows boot to inspect for internal steering gear leaks.
If a leak is detected in the steering gear, repair or install a new steering gear. See - Service and Repair, or see - Service and Repair
- If a leak is detected in the power steering reservoir, install a new reservoir. See - Service and Repair
External Leak Check - Potential Power Rack-and-Pinion Steering Gear Leak Points
7. For information on power steering leak detection, refer to Component Tests.
8. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding.
9. If the cause is not visually evident, verify the symptom and see - Symptom Troubleshooting Chart - Power Steering or see Symptom Troubleshooting Chart - Suspension NVH.
Steering System Symptom Definitions
Drift/PullPull is described as a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight.
Drift describes what a vehicle with this condition does with the hands off the steering wheel.
- A vehicle-related drift/pull, on a flat road, can cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect.
- Drift/pull can be induced by conditions external to the vehicle such as wind or road camber.
Excessive Steering Wheel PlayExcessive steering wheel play is a condition in which there is too much steering wheel movement before the wheels move. A small amount of steering wheel free play is considered normal.
FeedbackFeedback is a roughness felt in the steering wheel when the vehicle is driven over rough pavement.
Lack of Assist or Inconsistent AssistLack of assist or inconsistent assist is experienced when the steering wheel effort is higher than normal. Hard steering can remain constant through the full turn or occur near the end of a turn. It is important to know the difference between hard steering/lack of assist and poor returnability/sticky steering.
Hard steering or lack of assist can result from either hydraulic or mechanical conditions. It is extremely important to know if this concern occurs during driving or during high-effort parking maneuvers.
NibbleSometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces and observed by the driver as small rotational oscillations of the steering wheel.
Poor Returnability/Sticky SteeringPoor returnability and sticky steering is used to describe the poor return of the steering wheel to center after a turn, or the steering correction, is completed.
ShimmyShimmy, as observed by the driver, is large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements.
Shimmy is usually experienced near 64 km/h (40 mph), and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface.
WanderWander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.