about 10 minutes to warm it up to its normal
Set RESERVOIR valve (15, figure 2-1) to IN if
an open loop hydraulic flow system is to be
j. Check the oil pressure on ENGINE OIL PRES-
used for testing. Set the RESERVOIR valve to
SURE gage (2, figure 2-1). The needle of the
OUT if a closed loop hydraulic flow system is
to be used.
gage should be in the green region on the gage.
k. Check the reading on AMMETER (3, figure
d. Start the engine, using the procedures of
2-1). The AMMETER needle should be a little
to the right of center scale.
e. Turn COMPENSATOR SHUTOFF VALVE (17)
1. After the engine has warmed up, adjust
fully clockwise to the closed position.
THROTTLE (3, figure 2-2) to bring the engine
Adjust VOLUME control (14) to the position
speed up to 2000 RPM. Read engine speed on
where FLOW INDICATOR GPM (11) indicates
TACHOMETER HOUR METER (1, figure 2-l).
the GPM flow needed for the system you are
Lock the THROTTLE at the setting that pro-
going to test. AS you turn the VOLUME con-
duces 2000 RPM (NO LOAD); 1800 RPM at
trol clockwise, you increase the flow. Lock
the VOLUME control when you have the correct
2-4. OPERATION FOR EXTERNAL SYSTEM TEST-
ING . To test an aircraft hydraulic system, operate
Set HIGH PRESS BYPASS VALVE control (19)
the test stand as follows:
Adjust HIGH PRESS RELIEF VALVE (18) so
that it relieves pressure at about 200 PSI a-
bove the system pressure needed for test. As
you turn this valve clockwise, you increase the
Do not connect or disconnect hose assem-
pressure relief point. Read system pressure
blies while the system is under pressure,
on FLUID PRESSURE GAGE (5).
when HIGH PRESS BYPASS VALVE (19,
Turn COMPENSATOR SHUTOFF VALVE (17)
figure 2-1) is set to CLOSED, or when
fully counterclockwise to open. The system
FLOW CONTROL VALVE (12, figure 2-1)
pressure reading on FLUID PRESSURE GAGE
(5) will drop.
Turn PRESSURE COMPENSATOR (16) clock-
wise until FLUID PRESSURE GAGE (5) reads
slightly above the highest pressure of the sys-
Review the technical manuals for the sys-
tem you are going to test. Lock the PRESSURE
tem that you are going to test. During
COMPENSATOR at this setting.
testing, check FLUID PRESSURE GAGE
Turn FLOW CONTROL VALVE (12) counter-
(5, figure 2-1) and SUCTION PRESSURE
clockwise to the open position. Proceed with
GAGE (7, figure 2-1) for erratic or ab-
the specified tests of the aircraft hydraulic
Set RESERVOIR valve (15) to IN if the test
a. Check to make sure that all preliminary setup
stand reservoir is to be used. Set this valve
procedures of paragraph 2-2 have been done.
to OUT if the reservoir of the system under
b. Check to see that the outlet hose assembly is
test is to be used.
tightly connected between the 1/2" OUTLET
port of the test stand and the inlet port of the
2-5. SHUT-DOWN. To shut down the test stand
system to be tested. Check to see that the
after use, do the following:
return hose assembly is tightly connected be-
tween the 3/4" SUCTION RETURN port of the
a. Set HIGH PRESS BYPASS VALVE control (19,
test stand and the outlet port of the system to
figure 2-1) to OPEN.
b. Turn FLOW CONTROL VALVE (12, figure 2-1)
fully clockwise to close.
c. Turn PRESSURE COMPENSATOR (16, figure
2-1) fully counterclockwise to open.
Always start with RESERVOIR valve (15)
d. Idle the engine of the test stand for about five
set to IN. Never set the RESERVOIR
valve to OUT while FLOW CONTROL
e. Set IGNITION SWITCH (2, figure 2-2) to OFF.
VALVE (12) is closed, or when a complete
f. Remove the hose assemblies from the test
hydraulic loop is not provided. Cavitation
stand and the system that you tested. Install
and damage to the test stand pump may
dust plugs on both ends.
occur if you disregard this caution.