Power Steering System Test Procedure
PROCEDURE
- J 5176-E Power Steering Gauge
- J 5421-02 Thermometer
The power steering system test is a method used in order to identify and isolate hydraulic circuit difficulties. Prior to performing this test, make the following inspections and the necessary corrections.
1. Inspect the pump reservoir for the proper fluid level.
2. Inspect the pump belt for proper tension.
3. Inspect the pump drive pulley condition.
4. Perform the Diagnostic System Check. Refer to Variable Effort Steering System Check in Variable Effort Steering.
Testing and Inspection
5. Perform the following procedure:
5.1. Place a container under the steering gear or the pump in order to catch the fluid when disconnecting or connecting the hoses.
5.2. With the ignition OFF, disconnect the pressure hose at the steering gear or at the power steering pump.
5.2.1. Install the J5176-E to both hoses.
5.2.2. Position the gauge between the shutoff valve and the pump.
5.2.3. Open the shutoff valve.
5.3. Remove the filler cap from the pump reservoir and check the fluid level.
5.3.1. Fill the pump reservoir with power steering fluid to the full mark on the dipstick.
5.3.2. While momentarily holding the steering wheel against the stop, start the engine and check the connections at the J5176-E for leaks.
5.4. Bleed the system.
Important: Perform all the tests with the engine idling at the normal operating temperature.
5.5. Insert the J 5421-02 in the reservoir filler opening.
Move the steering wheel from stop to stop several times until the thermometer indicates the power steering fluid in the reservoir has reached a temperature of 65° - 77° C (150° - 170° F).
Important: In order to prevent scrubbing flat spots onto the tires, do not turn the steering wheel more than five times without rolling the vehicle in order to change the tire-to-floor contact area.
5.6. Start the engine and check the pump fluid level.
5.6.1. Add power steering fluid, if required.
5.6.2. When the engine is at normal operating temperature, the initial pressure reading on the gauge, with the valve open, should be in the 550-860 kPa (80-125 psi) range.
5.6.3. If this pressure is in excess of 1380 kPa (200 psi), check the hoses for restrictions.
5.6.4. Check the poppet valve for proper assembly.
5.7. Fully close the gate valve three times.
Notice: Do not leave the valve fully closed for more than 5 seconds, or the pump could be damaged internally. Record the highest pressures attained each time.
- If the pressures recorded are within 9,308-9,998 kPa (1,350-1,450 psi) or, for the C3500HD 10,101-10,446 kPa (1,465-1,515 psi) and the range of readings are within 345 kPa (50 psi), the pump is functioning within specifications.
- If the pressures recorded are high, but do not repeat within 345 kPa (50 psi), the flow controlling valve is sticking.
- Remove the valve.
- Clean the valve.
- Remove any burrs using crocus cloth or a fine hone.
- Flush the system if the system contains dirt.
- If the system is exceptionally dirty, disassemble the pump and the gear.
Clean, flush, and reassemble the system before further usage.
- If the recorded pressures are constant but between 690 kPa (100 psi) and 9,308 kPa (1,350 psi), replace the flow control valve and recheck the system.
- Replace the rotating group in the pump if the pressure remains low.
5.8. If the pump pressures are within specifications, leave the valve open and turn the steering wheel to both stops.
5.9. Record the highest pressures and compare with the maximum pump pressure recorded.
If this pressure cannot be reached in at least one side of the gear, the gear is leaking internally.
Disassemble and repair the gear.
5.10. Shut the engine OFF.
5.11. Remove the testing gauge.
5.12. Reconnect the pressure hose.
5.13. Check the fluid level.
Make the necessary repairs.
5.14. If the problem still exists, examine the steering and the front suspension.