CONVERTING THE AH-1G/UH-1C/M HELICOPTER HYDRAULIC SYSTEMS
FROM MIL-H-5606 TO MIL-H-83282 HYDRAULIC FLUID
B-1. Ground Servicing Equipment Required.
c. Disconnect the tail rotor servo at the control
tube and actuate the piston four full strokes to discharge
AH-1G/Q/S, series/UH-1C/M helicopter hydraulic
residual fluid from the cylinder.
systems from MIL-H-5606 to MIL-H-83282 hydraulic fluid.
d. Drain all hydraulic fluid from the emergency
B-2. Items to be Manufactured.
accumulator. Refill the accumulator with MIL-H-83282,
slosh fluid and drain.
Drain line from ground test coupling (return) on
B-5. Component Replacement.
B-3. Removal of Components.
a. Install both hydraulic pumps. Fill pumps with
MIL-H-83282 through the case drain port. Install all
a. Disconnect the suction hose from the reservoir
remaining hoses to the pumps.
to the hydraulic pump, # 1 System, at the pump. Allow
the fluid from the reservoir to drain into a receptacle.
b. Install pressure and return hoses to the
Repeat the above for the I# 2 system hydraulic pump.
hydraulic servo cylinders.
Drain the fluid from each system
Do not Inter-connect hydraulic hoses
reservoir sump using the drain plugs at
from one cylinder to the other.
the bottom of the reservoirs,
c. Connect control rods to the swashplates.
b. Disconnect all remaining hoses at the pumps
and remove the pumps. Drain all hydraulic hoses of fluid.
d. Install pressure and return hoses to the anti-
torque servo cylinder. Connect the control rod to the
c. Remove filter elements (4) from the hydraulic
modules. Clean and reinstall the bowls without the filter
e. Install the accumulator and hydraulic hose to
the accumulator. Charge the accumulator with nitrogen.
d. Discharge the accumulator and disconnect
hose at the accumulator, loosen holdown nuts and
B-6. Filling, Bleeding and Functional Testing.
remove accumulator. Drain hydraulic hose of fluid.
Refer to Appendix D or E for specific instructions
e. Disconnect and drain hydraulic hoses from
concerning conversion of ground servicing units.
main rotor servo cylinders (3).
a. Disconnect the return hose to the reservoir at
f. Disconnect and drain hydraulic hoses from
the ground test coupling, #1 system, and allow the hose to
anti-torque servo cylinder.
B-4. Component Flushing.
b. Connect drain line to the ground test coupling
and place unattached end in an open container.
a. To drain all hydraulic fluid from both hydraulic
pumps turn the splined shaft while pump is inverted. Turn
c. Attach pressure hose from hydraulic ground
shaft until fluid no longer drains from pressure and return
servicing unit to ground test coupling (pressure) #1
ports in the pump body. Fill pump through return port with
MIL-H-83282 and repeat the above procedure with both
d. Bring hydraulic pressure to 1000 psi and meter
hydraulic fluid into the aircraft hydraulic system while
b. Disconnect the control tube from each control
actuating the cyclic, collective, and
cylinder at the swashplate. Actuate the piston on each
cylinder four full strokes to discharge residual fluid from