Component Tests and General Diagnostics
Steering System
Component Tests
Power Steering Fluid Leak Test
NOTE: This test should only be carried out if a leak in the system has not been detected during a thorough visual inspection. Refer to Inspection and Verification. Inspection and Verification
1. Check the power steering fluid level. If necessary, add the specified power steering fluid.
2. Remove the power steering pump reservoir cap and tightly install the Power Steering Evacuation Cap to the power steering pump reservoir.
3. Install the hose from the fill adapter manifold tee to the Power Steering Evacuation Cap on the power steering pump reservoir.
4. Install the Vacuum Pump Kit to the Power Steering Evacuation Cap.
5. Using the Vacuum Pump Kit, apply 68-85 kPa (20-25 in-Hg) of vacuum to the power steering system.
6. Observe the vacuum gauge for 30 seconds. If the vacuum gauge reading drops more than 3 kPa (0.88 in-Hg) a leak is present.
7. Remove the Vacuum Pump Kit.
8. NOTICE: 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. With the engine at idle, raise the power steering fluid temperature to 74-80°C (165-176°F) by rotating the steering wheel fully to the left and right several times.
9. Visually inspect the system for leaks. If a leak is evident, repair as necessary. If a leak is not evident, add the specified UV fluorescent tracer dye to the power steering fluid. Use 14.78 mL (1/2 oz) of dye solution for every 1.89L (2 qt) of power steering fluid. For steering system fluid capacity, refer to Specifications.
10. NOTICE: 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. With the engine at idle, raise the power steering fluid temperature to 74-80°C (165-176°F) by rotating the steering wheel fully to the left and right several times.
11. NOTE: On vehicles with rack and pinion steering gear, it may be necessary to remove the bellows boot clamp from the steering gear bellows boots to inspect for internal steering gear leaks.
Using the 100W/12 Volt DC UV Lamp, inspect the system for traces of UV dye. Repair as necessary.
Steering Linkage
1. NOTE: Excessive vertical motion of the studs relative to the sockets may indicate excessive wear.
With the vehicle on the ground and the parking brake applied, start the vehicle and carry out the following:
- Have an assistant rotate the steering wheel left and right 360 degrees and watch for relative motion of the studs in the steering linkage ball sockets.
- Watch for loose steering gear mounting.
2. An additional check is with the Key ON Engine OFF (KOEO) and the front wheels raised off the ground. Grasp the wheel at the front and rear and watch for excessive play or binding in the joints while trying to steer the wheels.
3. Install new components if necessary. Tighten any worn, damaged or loose components.
Steering Gear Valve
1. With the vehicle in NEUTRAL, position it on a hoist. Refer to Maintenance/Service and Repair.
- Raise the vehicle until the front wheels are off the ground.
2. NOTE: Do not hold the steering wheel while carrying out this step.
Start the engine.
- If the steering wheel rotates in either direction (with no hand input), install a new steering gear.