Component Tests and General Diagnostics

Part 2 Of 2:

To properly test this vehicle's power steering system, the following tests should be performed, in the order presented.

TEST 1 - PRELIMINARY CHECKS
1. Check power steering fluid level.
2. Check accessory drive belt for slippage.


TEST 2-POWER STEERING SYSTEM HYDRAULIC TEST
1. Disconnect high pressure line at the steering gear and install Power Steering System Tester.
2. Open the gate valve on the power steering system tester.
3. Run engine until it has reached normal operating temperature. Replace any power steering fluid lost during power steering tester installation. Bleed system if necessary. (Refer to POWER STEERING SYSTEM BLEED procedure.)
4. With engine idling, record the power steering fluid pressure and flow rate. If the pressure reading is greater than 1034 kPa (150 psi), stop the engine and check power steering lines for restrictions.

IMPORTANT: Do not turn steering wheel while performing this test. This will lead to inaccurate results.

5. Slowly close the gate valve until 4827 kPa (700 psi) is indicated on the power steering tester. Record the power steering fluid pressure and flow rate. The flow rate observed should not drop 3.8 LPM (1 GPM) or more, replace the ring, rotor, and vanes in the pump. Also, check the pressure plate and thrust plates for wear. Replace if required.

IMPORTANT: Do not turn steering wheel while performing this test. This will lead to inaccurate results.

6. Fully close and open the gate valve three times.

NOTICE: Do not close the gate valve for more than five seconds at a time. This may damage the power steering pump.

IMPORTANT: Do not turn steering wheel while performing this test. This will lead to inaccurate results.

Record the power steering fluid pressure each time the valve is closed. All three readings should be within 345 kPa (50 psi) of each other. If not, replace the flow control valve.
7. With gate valve open, increase the engine speed to 1600 rpm and record the power steering fluid pressure and flow rate.

IMPORTANT: Do not turn steering wheel while performing this test. This will lead to inaccurate results.

The flow rate should not vary more than 3.8 LPM (1 GPM) from the flow rate recorded in step 4. If the flow rate does vary 3.8 LPM (1 GPM) or more, check that the flow control valve moves freely in the pump housing. Inspect valve for burrs. If present, remove with crocus cloth or a fine hone.
8. Turn the steering wheel all the way to the left, then all the way to the right. Record the power steering fluid pressure and flow rate at each stop. If the flow is greater than 3.8 LPM (1 GPM) at either stop, the steering gear is leaking internally and must be replaced.
9. After completing flow test, stop engine and remove power steering reservoir cap to release system pressure prior to removing analyzer.