TM 1-4920-446-13 & P
HP relief valve (10) must be set 200/250 psi higher than compensator control (6) to achieve desired pressure.
e. Open HP bypass valve (7).
f. Adjust the flow limit adjust control to the flow required by the aircraft being serviced. Observe the flowmeter.
g. Slowly close HP bypass valve (7).
2-15. Aircraft System Test. To test an aircraft system, proceed as follows:
a. Ensure the test stand has been prepared for operation (paragraph 2-7) and is properly connected to the aircraft.
b. Make certain that the aircraft system is filled, free of entrapped air and correctly pressurized.
Refer to the technical publication which applies to aircraft being serviced for the proper test procedures.
c. Set the outlet selector valve to point towards the 1/2 inch or 3/4 inch flow control outlet valve (12 or 13). Fully
open the selected valve.
d. Set selector valve (8) to filter out position.
e. Activate the test stand (25).
f. Slowly close the HP bypass valve (7).
g. Proceed with the aircraft system test as directed in the technical publication applicable to the aircraft being
h. Observe fluid pressure gauge (2). Adjust the compensator control (6) to obtain the required pressure for the spe-
i. Observe the flow indicator (17). Adjust the flow limit adjust (11) to obtain the required hydraulic fluid flow for the
aircraft being tested.
j. Monitor the temperature of the hydraulic fluid at the LP filter outlet by observing the fluid temperature gauge (4).
k. Occasionally, or as necessary, check the return pressure from the aircraft. Switch the selector valve (8) to the
suction pressure, boost pump position and observe boost pressure gauge (3).
l. After completing the hydraulic test of the aircraft, shut down the test stand using standard operating procedures