2.Allow the power steering pump fluid to cool to 130°F before testing is resumed.
3.With the engine at full governed R.P.M. close the shutoff valve and note that the flow reads 0. QUICKLY OPEN THE SHUTOFF VALVE, and note that the flow rate immediately returns to normal. Repeat this test once but do not allow fluid temperature to exceed 200°F.
If the flow rate does not immediately return to normal, pump repair or replacement is indicated.
RELIEF PRESSURE TEST & INTERNAL LEAKAGE TEST - POWER STEERING GEAR
1.To test the pressure relief valve and internal leakage of the power steering gear, it is necessary to prevent operation of the gear’s poppet valves contained in the piston. This can be accomplished by placing a steel block between the axle stop and the adjusting screw. The block should be a minimum of one inch thick and long enough to be inserted without danger of pinching fingers. Keep fingers clear of pinch points and be sure block is square to points of contact.
WARNING: Failure to follow these instructions can result in serious injury or damage to the equipment.
2.Check fluid temperature in the reservoir, thermometer reading should be approximately 130° at start of the test and the shut off valve on the flow meter must be totally open.
NOTE: Refer to Preliminary Instructions section of the service data.
3.Turn the steering wheel until the axle stops contact the spacer block. (See Figure 50) Apply sufficient torque to the steering wheel to assure the power steering gear control valve is completely open in the direction of the turn. At this time the pressure gauge will read the gear pressure relief setting. If the pressure reading is above
THERMOMETER | POWER STEERING | |
GEAR | ||
|
OIL
RESERVOIR
GAUGE
POWER STEERING PUMP | FLOW | SHUTOFF | |
VALVE | |||
| METER | ||
|
| ||
|
|
| |
FIGURE 49 |
|
|
AXLE STOP
FIGURE 50
1945 p.s.i. or below 1825 p.s.i. relief valve adjustment or repair is necessary.
CAUTION: When running this test, do not hold the torque on the steering wheel for more than 5 seconds beyond the time the pressure relief setting of the gear has been reached. It may damage the unit or cause the temperature of the oil to raise beyond 200°.
4.In order to test the steering gear for internal leakage it is necessary to TEMPORARILY adjust the setting of the power steering gear pressure relief valve above that of the power steering pump relief valve. To accomplish this install the appendix pressure relief valve test plug assembly 106773.
To install the plug assembly: (See Figure 7)
A.With the engine stopped, remove the pressure relief valve plug (3) sealing washer (4) adjusting shims (5) and spring(6).
B.Install the sealing washer on the test plug assembly (106773) then install the test plug assembly in the power steering gear valve body. Torque the test plug assembly to 66 - 73 pound feet.
5.Run the engine at idle. Turn the steering wheel until the axle stop contacts the spacer block. (See Figure 50) Apply a sufficient torque to the steering wheel to assure the power steering gear control valve is completely open in the direction of the turn. Observe the following.
PART NUMBER 106773
PRESSURE RELIEF VALVE TEST PLUG ASSEMBLY
24
