The test stand is now full and air free.

TM 55-4920-442-13&P

g. Replenish the hydraulic reservoir to the proper level (3/4 to 7/8 full) with hydraulic fluid conforming to MIL-H-

83282. Observe hydraulic oil gage.

2-8. The test stand is now full and air free.

2-9. Preliminary adjustments and control settings. The test stand system is filled with hydraulic fluid at the completion of

the procedures in paragraph 2-7. It is now necessary to set the stand controls to accommodate the test to be run.

a. Set the 4-way valve to the stand reservoir position.

b. Depress hp start pushbutton.

c. Set the selector valve to the LP filter inlet position.

d. Open HP flow control valve.

e. Slowly close HP bypass valve.

f. Adjust HP relief valve, located adjacent to HP filter, to closed. (Fully clockwise) position.

g. Adjust compensator control to achieve an output pressure of 3300 psi as indicated on high pressure gage.

h. Reset HP relief valve to obtain a reading of 3000 psi on the high pressure gage.

i. Adjust volume control to obtain a flow of 20 gallons per minute (GPM) as indicated on flowmeter.

j. Observe fluid flow through flow meter. If air is entrained, intermittently press bleed valve control until fluid is clear.

k. Decrease the hydraulic fluid flow to a minimum with volume control.

NOTE

HP relief valve must always be set 10 percent lower than compensator control to achieve

proper flow conditions.

l. Adjust compensator control and HP relief valve to achieve the correct pressure for the test to be run.

m. Shut down test stand and stop the HP pump in accordance with the procedures in paragraph 2-10.

2-10. Shutting down the test stand. After making the preliminary adjustments to be sure the test stand is functioning

properly or at the completion of a test or filling operation, the stand may be shut down by performing the following steps:

a. Open HP relief valve by turning completely counterclockwise.

2-3