Component Tests
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. Remove the power steering pump reservoir cap and check the power steering fluid level. If necessary, add the specified power steering fluid.
2. Tightly install the Power Steering Evacuation Cap onto the reservoir and connect the Vacuum Pump Kit to the Evacuation Cap.
3. Using the Vacuum Pump Kit, apply 68-85 kPa (20-25 in-Hg) of vacuum to the power steering system.
4. 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.
5. Remove the Vacuum Pump Kit.
6. Start the engine and insert the Dial Thermometer into the Evacuation Cap.
7. NOTICE: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump may occur.
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.
8. Stop the engine and 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.
9. Start the engine.
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.
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. Stop the engine and inspect the system for traces of UV dye using the 100W/12 Volt DC UV Lamp. Repair as necessary.
Pump Flow and Pressure Test - Vehicles With Hydro-Boost(R)
WARNING: Do not touch the flowmeter during the test procedure or for several minutes after use. The flowmeter may become hot during use and can burn unprotected skin. Failure to follow this instruction may result in serious personal injury.
NOTE: For power steering pump flow, pressure and relief pressure specifications, refer to General Specifications/Power Steering Pump.
1. NOTICE: Make sure that the connection point will not interfere with any of the engine accessory drive components or drive belts. Damage to the analyzer or accessory drive components can occur.
Install the Power Steering Adapters and the Power Steering Analyzer Kit between the pressure line and the pressure inlet port of the Hydro-Boost(R) brake booster. Make sure the power steering analyzer gate valve is fully open.
2. Place a Dial Thermometer in the power steering pump reservoir.
3. Check the power steering fluid level. If necessary, add specified power steering fluid.
4. Install a digital tachometer.
5. NOTICE: Do not hold the steering wheel against the stops for an extended amount of time. Damage to the power steering pump can occur.
Start the engine. Place the transmission in NEUTRAL. Set the parking brake. Raise the power steering fluid temperature to 74-80°C (165-175°F) by rotating the steering wheel fully to the left and right several times.
6. With the steering wheel in the straight-ahead position, set the engine at idle. Record the flow rate and pressure readings.
- If the flow rate is below the flow rate specification, check the power steering pump-to-brake booster pressure line for kinks and restrictions.
- If the pressure reading is above the pressure specification, check all other power steering hoses and the fluid cooler for restrictions.
7. Partially close the gate valve to obtain 750 psi. Set the engine speed at idle. Record the flow rate.
- If the flow is less than the specified flow rate, install a new power steering pump.
8. NOTICE: Do not allow the gate valve to remain closed for more than 5 seconds.
Completely close and partially open the gate valve 3 times. Record the pressure relief valve actuation pressure reading.
- If the pressure does not meet the relief pressure specification, then install a new power steering pump.
9. Fully open the gate valve. While reading the pressure gauge, have an assistant gradually apply the brake pedal until the relief pressure is reached and then release the brake pedal (pressure should quickly build and release). Have the assistant gradually apply the brake pedal again to verify consistency.
- If the relief pressure can not be reached (brake pedal should be hard), install a new Hydro-Boost(R) brake booster. Refer to Power Brake Actuation Service and Repair.
- If the pressure returns slowly or sticks, check the brake pedal and bracket for sticking or binding. If the brake pedal and bracket are OK, install a new Hydro-Boost(R) brake booster. Refer to Power Brake Actuation Service and Repair.
10. NOTICE: Do not hold the steering wheel against the stops for an extended amount of time. Damage to the power steering pump can occur.
Have an assistant turn the steering wheel to the left and right stops. Record flow rate and pressure readings at the stops.
- The pressure reading at both stops should be nearly the same as the pump relief pressure.
- The flow rate should drop below 1.9L/min (0.5 gal/min).
- If the pressure does not reach the pump relief pressure or the flow rate does not drop below the specified value, excessive internal leakage is occurring. Install a new steering gear as necessary. Refer to Power Steering Service and Repair.
11. Have an assistant turn the steering wheel slightly in both directions and release quickly while watching the pressure gauge.
- The pressure reading should move from the normal back pressure reading and snap back as the steering wheel is released.
- If the pressure returns slowly or sticks, the rotary valve in the steering gear is sticking or the steering column is binding. Check the steering column and linkages before repairing the steering gear.
Steering Gear Valve Test
1. With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting 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. Refer to Power Steering Service and Repair.
Steering Gear Grunt/Shudder Test
1. Start and run the vehicle to operating temperature.
2. Set engine idle speed to 1,200 rpm.
3. NOTICE: Do not hold the steering wheel against the stops for an extended amount of time. Damage to the power steering pump will occur.
Rotate the steering wheel to the RH stop, then turn the steering wheel 90 degrees back from that position. Slowly turn the steering wheel back and forth approximately one-twelfth of a full turn.
4. Turn the steering wheel another 90 degrees. Slowly turn the steering wheel back and forth approximately one-twelfth of a full turn.
5. Repeat the test with the power steering fluid at different temperatures.
6. If a light grunt is heard or a low (50-200 Hz) shudder is present, this is a normal steering system condition.
7. If a loud grunt is heard, or a strong shudder is felt, purge the power steering system. Refer to Power Steering System Purging Power Steering System Purging. If a loud grunt or strong shudder still exists, check the power steering lines/hoses for restrictions or damage and repair as necessary. Refer to Power Steering Power Steering System - Exploded View. If the lines/hoses are OK, install a new steering gear. Refer to Power Steering Service and Repair.