Hydraulic Flow And Pressure Test
The following procedure is used to test the operation of the power steering system on this vehicle. This test will provide the Gallons Per Minute (GPM) or flow rate of the power steering pump along with the maximum relief pressure. Perform this test anytime a power steering system problem is present. This test will determine if the power steering pump or power steering gear is not functioning properly. The following test is performed using the (special tool #6815, Kit, Power Steering) (with appropriate hoses) and adapters from (special tool #6893A, Kit, Power Steering). Refer to SPECIAL TOOLS .
- Check power steering belt to ensure it is in good condition and adjusted properly.
- Assemble the power steering analyzer (3) as follows:
- Gauge end (inlet) of (special tool #6800, Analyzer, Power Steering) (3) - (special tool #6905, Assembly, Hose) (6), (special tool #6713, Hose, Power Steering) (4), (special tool #6844, Adapter, Power Steering (Truck)) (5)
- Valve end (outlet) of Flow Meter And Gauge (special tool #6800, Analyzer, Power Steering) (3) - (special tool #6959, Assembly, Hose) (1), (special tool #6826, Adapter, LH P/S Tester) (2).
- Unthread pressure hose tube nut at power steering pump.
- Connect (special tool #6844, Adapter, Power Steering (Truck)) (5) to pressure fitting on power steering pump. Tighten tube nut to specifications. Refer to TECHNICAL SPECIFICATIONS .
- Connect power steering pressure hose to Adapter Fitting (special tool #6826, Adapter, LH P/S Tester) (2). Tighten tube nut to specifications. Refer to TECHNICAL SPECIFICATIONS .
- Open the analyzer test valve completely.
- Start engine and allow to idle long enough to circulate power steering fluid through analyzer flow meter and hoses.
- Shut off engine and check fluid level; add fluid as necessary. Repeat and. Refer to 7. until air is bled from system. Refer to 8.
- Start engine and allow to idle.
- The analyzer gauge should read below 2068 kPa (300 psi). If above, inspect hoses for restrictions and repair as necessary. The initial pressure should be in range of 689-1896 kPa (100-175 psi). The flow meter should read above 5.7 LPM (1.5 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.
- Close flow meter valve fully three times and record highest pressure indicated each time. All three readings must be above specifications and within 690 kPa (100 psi) of each other.
- If power steering pump pressures are above specifications, but not within 690 kPa (100 psi) of each other, replace power steering pump.
- If pressures are within 690 kPa (100 psi) of each other, but are below specifications, replace power steering pump.
If the power steering pump requires replacement. Refer to 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.
- 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 690 kPa (100 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 GEAR, REMOVAL .
| ENGINE TYPE | RELIEF PRESSURE |
|---|---|
| GASOLINE | 10, 600 kPa (1540 psi) |
| DIESEL | 11, 307 - 11, 997 kPa (1640 - 1740 psi) |