VALVE AND CONTROL SETTINGS.

TM 55-4920-335-14

g. After engine starts, slowly close choke control (26)

operating procedures outlined in paragraph 3-4 apply to

until engine is operating normally with choke in fully closed

system testing and filling using the Test Stand reservoir as

position.

source of hydraulic fluid. The operating procedures using the

aircraft reservoir as source of hydraulic fluid are the same as

h. Operate engine at 1000 to 1400 rpm as read on tach-

outlined in paragraph 3-4 except prior to operating procedures,

hourmeter (21, figure 3-1) for approximately 10 minutes to

close reservoir shutoff valve (1, figure 3-1).

warm engine up to normal operating temperatures.

3-6. PROCEDURES DURING OPERATION. During operation

i. Adjust engine throttle control (24, figure 3-1) until

of the Test Stand, periodically check the following:

1800 rpm is read on tach-hourmeter (21).

a. If fault indicators (5 or 10, figure 3-1) light, shut-down

Place fuel level gage switch (23) in ON position.

Test Stand.

k. Observe engine oil pressure gage (22) for indication

b. Move pressure selector valve (12, figure 3-1) to

of proper oil supply to the engine. Shut down engine

FILTER INLET position and read system condition on gage (9).

immediately if oil pressure gage does not indicate proper oil

Shutdown unit if supply pressure is below 13" Hg Vac.

pressure.

c. If an emergency should arise (ruptured hydraulic hose

3-4. VALVE AND CONTROL SETTINGS. Observe the

in aircraft, etc.) open bypass valve (19, figure 3-1) to relieve

following procedures in setting valves and controls:

pressure and stop flow of hydraulic fluid to aircraft.

a. Close 1/2 inch flow control valve (16, figure 3-1) and

d. Periodically check ammeter (2, figure 3-1) for

3/4 inch flow control valve (14).

condition of electrical system: fluid level indicator (8) for level of

fluid remaining in reservoir; fuel level gage (20) for amount of

Close compensator shutoff valve (18).

fuel remaining in tank, and engine oil pressure gage (22) for

condition of engine.

c. Open high pressure gage shutoff valve (3).

Open

reservoir shutoff valve (1).

e. Check temperature of hydraulic fluid in system at

gage (11, figure 3-1). If temperature of fluid is above 160

d. Adjust pump delivery to requirements using volume

degrees F, open bypass valve (19) and allow fluid to circulate

control (4, figure 1-3) as indicated by flow indicator (7, figure

until temperature drops. After temperature has reduced to

3-1). Turn handwheel of volume control clockwise to increase

operating range, close bypass valve and resume testing

delivery, counterclockwise to decrease delivery. A lever is

operations.

provided under the handwheel to securely lock volume control

in position.

3-7. STOPPING TEST STAND. Use the following procedure

to stop the Test Stand:

Close bypass valve (19, figure 3-1).

Open bypass valve (19, figure 3-1).

f. Adjust high pressure relief valve (17, figure 3-1) to

relieve pressure at approximately 200 psi above the system

Close flow control valve (14, or 16, figure 3-1).

pressure of the unit on test. Clockwise rotation of the relief

valve knob increases pressure setting, counterclockwise

c. Use throttle control (24, figure 3-1) to idle engine for 5

rotation decreases pressure setting. Accuracy of the setting

minutes to normalize engine temperature.

should be checked on aircraft instruments after start of testing.

Place ignition switch (25, figure 3-1) in OFF position.

g. Open compensator shutoff valve (18, figure 3-1) and

adjust compensator control (6, figure 1-3) until high pressure

3-8. PROCEDURES AFTER OPERATION. When testing

gage (6, figure 3-1) indicates pressure of the unit being tested.

operations have been completed and unit is shut-down,

Lock control in position with lock nut under knob.

perform the following steps to secure the Test Stand:

Open bypass valve (19, figure 3-1).

Close reservoir s hutoff valve (1, figure 3-1).

i. Place outlet selector valve (15, figure 3-1) in 1/2 inch

b. Do not connect or disconnect any hoses with bypass

or 3/4 inch outlet position.

valve (19) closed.

Open flow control valves (14 or 16, figure 3-1).

c. Disconnect and cap all external hoses.

Place

protective caps on outlet ports.

k. Close bypass valve (19, figure 3-1) and proceed with

the test operation per manufacturer's specifications for the unit

d. Close control panel door and any other doors that

being tested.

were opened during operation.

3-5.

OPERATION WITH AIRCRAFT RESERVOIR.

The

3-4