Observe temperature gauge (item 4, fig-
Verify that RESERVOIR selector valve
ure 2-18) for an increase of approximately 10 degrees.
dual manifold BYPASS/FLUSH valve is closed.
Repeat steps (3) and (4) until fluid temper-
ature is high enough to illuminate the SYSTEM READY
Close the HIGH PRESSURE BYPASS
Set hydraulic pressure by placing PRES-
SURE switch to the INCREASE position until pressure
reaches 2500 PSIG as indicated on the OUTPUT PRES-
Ensure that hydraulic load connections
Open BYPASS/FLUSH valve on the Dual
Service Manifold until pressure drops to 2000 psig.
to ON and observe that output light illuminates. (This
opens the load select valve that applies AGPU hydraulic
power to the dual manifold).
Continue operations for approximately 5
minutes. If the hydraulic module has not been operated
Open the BYPASS/FLUSH (smaller)
tinue operation for 30 minutes.
manifold turn. The SYSTEM READY light (item 5,
because of temperature drop caused by cold hose fluid.
Wait until SYSTEM READY light (item 5,
Failure to reduce system pressure prior to shut-
ting down the hydraulic power can cause dam-
age to the pressure compensator motor on the
Close the BYPASS/FLUSH (smaller)
hydraulic pump and the limit switch.
Reduce system pressure to 500 - 700 psi.
to OFF (down position) and observe that output light
Set OUTPUT switch to OFF.
Set RETURN BYPASS position to OFF. If
Hold PRESSURE switch (item 3, figure
dual servicing is required go to step 13.
to the DECREASE position while watching the
OUTPUT PRESSURE gauge (item 7, figure 2-18). Re-
Remove the cap from the high-pressure
duce pressure to 500 psig.
GSE port on the aircraft to be serviced. Disconnect the
high-pressure adapter hose from the dual manifold and
immediately connect to the aircraft without putting the
Remove the cap from the return ground
ports on the aircraft to be serviced. Disconnect the re-
turn adapter hose from the dual manifold and reconnect
When hydraulic power is turned on, the hy-
draulic hose will be under extremely high
to the aircraft.
pressure. Make sure that all quick disconnect
fittings are secure, and hoses are not kinked.
Replace caps and plugs in the dual man-
Injury from flailing hoses could result. Wear
ifold and return to the AGPU.
proper gloves and eye protection (goggles or
face shield) when operating hydraulic equip-
If the aircraft servicing operation requires
dual system operation, purge the 2 additional high pres-
sure adapters hoses using the following steps:
Verify that all hoses connections are se-