TM 55-1730-229-34
AG 320A0-MME-000
TO 35C2-3-473-2
TM 1730-34/1
CHAPTER 8
MAINTENANCE OF HYDRAULIC SYSTEM
Section I.
DESCRIPTION OF HYDRAULIC SYSTEM
8 - 1 . DESCRIPTION. T h e h y d r a u l i c s y s -
This fluid is
a hydrau-
cooling and lubrication.
lic pump (mounted on engine gearcase), a
r o u t e d from the pump case drain back to
The pump receives elec-
h y d r a u l i c module, a dual manifold, and
the reservoir.
The hydrau-
trical commands, s e t b y t h e o p e r a t o r ,
h y d r a u l i c hoses and lines.
lic
system provides adjustable high
f r o m the hydraulic module control panel
pressure hydraulic power up to 3,300
for an increase or decrease of output
This
f l u i d pressure.
psig at 15 gpm to an aircraft.
h y d r a u l i c power c a n b e u s e d t o d r i v e
Module. T h e h y d r a u -
b . Hydraulic
aircraft hydraulic systems, f i l l a i r -
craft reservoirs, or flush aircraft hy-
d r a u l i c systems. Output pressure to the
controls (fluid and electrical) for the
h y d r a u l i c system. The module contains a
aircraft is adjusted by the operator at
t h e hydraulic module control panel. Hy-
nine-gallon reservoir with attachments
d r a u l i c pressure, once set, remains con-
for manual filling and draining, over-
stant regardless of the flow rate de-
f l o w , and removal of moisture from vent
m a n d e d by the aircraft (up to the maxi-
air that enters as fluid level changes.
H i g h pressure (3 micron) and return (10
m u m flow rate of 15 gpm). The hydraulic
s y s t e m uses fluid MIL-H-83282, or MIL-
filters have throw-away ele-
micron)
Fluid MIL-H-83282 is limited to
The filters have built-in elec-
H-5606.
ments.
-40F to
illuminate
the
temperature
ranges
from
that
trical
circuits
+125F.
CHANGE FILTER light on the control panel
w h e n the filter elements need changing.
a. Hydraulic Pump. The
T h e accumulator (pressurized with nitro-
hydraulic
p u m p (with pressure compensation con-
g e n ) , heat exchanger, gauge, valves and
trols enclosed) bolts to the engine/
plumbing complete the makeup of the hy-
gearcase pump mounting pad.
draulic module.
The pump
i s driven by the engine/gearcase at ap-
c . D u a l M a n i f o l d . A separate dual
p r o x i m a t e l y 8,000 rpm.
For units not
requiring hydraulic power, a spacer is
provided t o b o l t b e t w e e n t h e e n g i n e /
hydraulic system to accommodate the need
This spacer dis-
g e a r c a s e and pump.
f o r dual outlet and return connections.
The single input is branched to two
c o n n e c t s the pump from the drive gear.
This
eliminates
unnecessary
e q u a l o u t p u t l i n e s , a n d two returns are
wear on
combined i n t o a s i n g l e r e t u r n p a t h .
pump, and reduces load on engine (since
t h e pump must maintain a minimum 500
V a l v e s and fluid ports are provided for
for self-lubrication).
psig
pressure
f i l l i n g and draining hoses.
T h e hydraulic system must never be op-
d. Hoses and Lines. Plumbing be-
erated without sufficient hydraulic
fluid , or pump will be damaged.
The
t w e e n the pump and module consists of
fixed tubing with sections of hose at
p u m p receives a low pressure fluid from
The hoses be-
t h e hydraulic module reservoir and sup-
t h e end near the pump.
tween the hydraulic module and dual
The output
T h e pump is designed to allow hydraulic
manifold are 30 feet long.
8-1