gage to check the accuracy of the fluid pressure
nection from the inlet to the outlet side of the
low pressure filter, thereby determining the
condition of the filter element.
34. Filter Pressure Gage
37. Gage Dampener Precharge Valve
The filter pressure gage (6, fig. 9), mounted
on the test stand control panel, is a needle-indi-
The gage dampener precharge valve (22, fig.
cating, direct-reading, pressure and vacuum
9), extending through the test stand control
actuated, compound-type gage. When used in
panel, is provided to precharge the gage damp-
conjunction with the pressure selector valve,
ener with air to serve as a cushion in the hy-
the filter pressure gage indicates pressure drop
draulic system, dampening pulsations.
through the low pressure filter. An indicated
38. Outlet Selector Valve
pressure drop of 20 psi necessitates replace-
ment of the low pressure filter element.
The outlet selector valve (16, fig. 9), mounted
on the test stand control panel, is a 4-way, plug-
35. Filter Pressure Gage Tap
type valve, providing a means of selecting
The filter pressure gage tap (26, fig. 9), ex-
either the ½ in. or ¾ in. outlet connections of
the test stand.
tending through the test stand control panel,
provides a means of connecting a test gage to
39. Fluid Temperature Gage
check the accuracy of the filter pressure gage
The fluid temperature gage (4, fig. 9), cen-
trally located at the top of the test stand control
36. Pressure Selector Valve
panel, is a needle-indicating, direct-reading
The pressure selector valve (8, fig. 9), located
temperature gage graduated from --20 to 240
in the upper right-hand corner of the test stand
degrees Fahrenheit in increments of 5 degrees.
During operation the indicated fluid tempera-
control panel, is a two-way, plug-type valve
utilized to switch the filter pressure gage con-
ture should never exceed 160°.
Section Ill. OPERATION UNDER USUAL CONDITIONS
responding outlets of the aircraft to
be tested. Keep unused couplings
Instructions in this section are published for
capped with the dust protective caps
the information and guidance of personnel re-
(10, 11, and 12).
sponsible for operation of the aircraft hydraulic
b. Electrical Starting.
test stand. It is essential that the operator
(1) Open the fluid bypass valve (27, fig.
knows how to perform every operation for
9) by turning the handle fully counter-
which the equipment is capable.
41. Starting the Test Stand
(2) Pull the choke control (5, fig. 10) out.
a. Preparation for. Starting.
(3) Pull the throttle control (4) to one-
quarter open position.
(1) Set the brake lever assembly (8, fig. 1)
(4) Place the ignition switch (1) in the
securing the test stand in position.
(2) Open the engine compartment and con-
(5) Push the starter switch (2) until en-
trol panel door assemblies.
Caution: Always keep engine com-
partment top and side doors open
(6) Open the choke control until the engine
(3) Perform the before-operation services
(7) Operate the engine at 1000 to 1400
outlined in paragraph 54.
rpm for approximately 10 minutes to
(4) Connect the coupling halves (7, 8, and
warm engine up to normal operating
9, fig. 2) of the test stand to the cor-