Component Tests and General Diagnostics
POWER STEERING FLOW AND PRESSURE TESTWARNING: TO PREVENT PERSONAL INJURY, SAFETY GOGGLES SHOULD BE WORN AT ALL TIMES WHILE PERFORMING ANY TEST PROCEDURES ON THE POWER STEERING SYSTEM.
The following procedure is to be used to test the operation of the power steering system on this vehicle. This test will provide the flow rate of the power steering pump along with the maximum relief pressure. This test is to be performed any time a power steering system problem is present to determine if the power steering pump or power steering gear is not functioning properly. The following flow and pressure test is performed using the Power Steering Analyzer Kit, Special Tool 6815, hoses, Special Tools 6905 and 6959, and adapters, Special Tool 8185A.
1. Assemble hoses on Power Steering Analyzer, Special Tool 6815, as shown. Install Pressure Hose, Special Tool 6905 (in 6893 kit), in the inlet fitting on Power Steering Analyzer flow meter. Install Pressure Hose, Special Tool 6713 (in 6815 kit) on 6905. Install Pressure Hose, Special Tool 6959, in the outlet fitting on Power Steering Analyzer flow meter.
2. Install Adapter Fitting, Special Tool 8185-1A, on the end of Pressure Hose, Special Tool 6713. Install Adapter Fitting, Special Tool 8185-2, on Pressure Hose, Special Tool 6959.
3. Raise the vehicle.
4. Unscrew the tube nut and disconnect the power steering fluid pressure hose from the power steering gear.
5. Connect the vehicle's power steering pressure hose to Adapter Fitting, Special Tool 8185-2, connected to the analyzer. Tighten the tube nut to a torque of 47 Nm (35 ft. lbs.). Route the hoses away from the exhaust system as well as possible.
6. Connect Adapter Fitting, Special Tool 8185-1A, which is connected to the analyzer outlet hose (valve end), to the power steering gear port. Tighten the tube nut to a torque of 47 Nm (35 ft. lbs.).
7. Being careful not to kink or pinch the analyzer hoses, lower the vehicle to the ground.
TEST PROCEDURE
1. Completely open the valve on the Power Steering Analyzer flow meter.
2. Start the engine and let idle long enough to circulate power steering fluid through the analyzer and hoses, until the air is out of the fluid. Shut the off engine.
3. Check the power steering fluid level and add fluid as necessary. Start the engine again and let idle.
4. The analyzer gauge should read below 862 kPa (125 psi). If above, inspect the hoses for restrictions and repair as necessary. The initial pressure should be in the range of 345 - 552 kPa (50 - 80 psi). The flow meter should read between 1.5 and 1.7 GPM.
CAUTION: The following test procedure step involves testing maximum pump pressure output and flow control valve operation. Do not leave valve closed for more than five seconds as the pump could be damaged.
NOTE: Power steering pump maximum relief pressure is 9308 to 9998 kPa (1350 to 1450 psi.).
5. Close the flow meter valve fully three times and record highest pressure indicated each time. All three readings must be above specifications and within 345 kPa (50 psi) of each other.
- If the power steering pump pressure's are above specifications, but not within 345 kPa (50 psi) of each other, replace the power steering pump.
- If the pressure's are within 345 kPa (50 psi) of each other, but below specifications, replace the power steering pump.
If the power steering pump requires replacement, refer to Power Steering Pump for the removal and installation procedure.
CAUTION: During the next step, do not force the pump to operate against the stops for more than 5 seconds at a time as pump damage may result.
6. Completely open the valve on the Power Steering Analyzer flow meter. Turn the steering wheel to the extreme left until the stop in the steering gear is met, then turn the steering wheel to the right until the right stop is met. Record the highest indicated pressure at each position. Compare the recorded readings to the specifications. If the highest output pressure reading against one stop is not within 345 kPa (50 psi) of the highest reading at the other stop, the steering gear is leaking internally and must be replaced.
If the power steering gear requires replacement, refer to POWER STEERING GEAR for the removal and installation procedure.