Hydraulic Flow and Pressure Test
HYDRAULIC FLOW AND PRESSURE TEST
WARNING: 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 (Gallons Per Minute (GPM)) of the power steering pump along with the maximum relief pressure. Perform this test any time a power steering system problem is present. This test will help determine if the power steering pump or power steering gear is not functioning properly. The test is performed using tools in the Power Steering Analyzer Kit 6815 with appropriate hoses and adapters. Tools and Equipment
1. Check the power steering belt to ensure it is in good condition and adjusted properly.
2. Assemble the following hoses and adapters on the Flow Meter And Gauge 6800 (1):
a. Gauge end (inlet) - Hose 6959 (2), Adapter Fitting 8185-2 (3)
b. Valve end (outlet) - Hose 6905 (4) (in 6893 kit), Hose 6713 (in 6815 kit), Adapter Tube 8185-1A
3. Raise and support the vehicle. Service and Repair
4. Unthread the tube nut (2) and disconnect the power steering fluid pressure hose from the power steering gear (1).
5. Connect the vehicle's power steering pressure hose (4) to Adapter Fitting 8185-2 (3) (on Hose 6959 (2) leading to Analyzer inlet). Tighten the tube nut to specifications. Specifications
6. Connect Adapter Fitting 8185-1A (6) (on Hose 6713 (5) leading to Analyzer outlet), to the open power steering gear (1) port. Tighten the tube nut to pressure hose specifications. Specifications
7. Route the hoses away from the exhaust system as well as possible.
NOTE: When the vehicle is lowered, make sure the hoses do not kink or pinch, or come in contact with the exhaust system.
8. Lower the vehicle.
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 pressures are above specifications, but not within 345 kPa (50 psi) of each other, replace the power steering pump.
- If the pressures are within 345 kPa (50 psi) of each other, but below specifications, replace the power steering pump.
If the power steering pump requires replacement, Power Steering Pump - Removal.
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, Steering Gear - Removal.