Bendix Commercial Vehicle Systems COMPACT 500 9/87 - Manual (Page 24)

24
PART NUMBER 106773
PRESSURE RELIEF VALVE TEST PLUG ASSEMBLY
FIGURE 50
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
AXLE STOP
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.
FIGURE 49
OIL
RESERVOIR
THERMOMETER
POWER STEERING PUMP FLOW
METER
SHUTOFF
VALVE
GAUGE
POWER STEERING
GEAR