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MODEL 182 & T182 SERIES SERVICE MANUAL
e.
Remove vacuum pump from mounting studs on
e.
Position new mounting pad gasket on mounting
engine.
studs on engine.
f.
Remove elbow from pump and retain if it is re-
f.
Position vacuum pump on mounting studs.
usable.
g.
Secure pump to engine with flat washers, new
lockwashers, and nuts.
Discard any twisted fittings or nuts with
rounded corners.
Always replace all lockwashers with new ones
when installing a new vacuum pump.
Tighten
15-28B.
MOUNTING PAD INSPECTION.
all four mounting nuts (4) to 50 to 70 pound-
a.
Check condition of the AND 200,0 pad seal.
If
inches.
the seal shows any signs of oil leakage, replace the.
seal.
Replace seal if there is any doubt as to its
h.
Connect hose to inlet side of vacuum pump.
serviceability.
procedures in Section 11.
15-28C.
INSTALLATION OF VACUUM PUMP.
15-29.
CLEANING.
In general, low pressure, dry
a.
Before installing a new vacuum pump, purge
compressed air should be used in cleaning vacuum
all lines in the system to remove carbon particles
system components.
Suction relief valve should be
or other pump components that may have been de-
washed with Staddard solvent, then dried with low-
posited in the lines by previous pump.
pressure air blast.
b. Consult the applicable Parts Catalog, the pump
vendor's application list, or the PMA label on the
pump box to verify that the pump is the correct model
Never apply compressed air to lines or
for the engine and/or system.
components installed in aircraft.
The
excessive pressures will damage gyros.
If an obstructed line is to be blown out,
c.
Position vacuum pump in a jaw-protected vise,
disconnect at both ends and blow from
with drive coupling downward.
instrument panel out
instrument panel out.
low-vacuum warning light is installed on the instru-
Pump housing should never be placed directly
ment panel.
The light is controlled by a vacuum
in a vise, since clamping across center hous-
switch which is teed into the line between the suction
ing will cause an internal failure of carbon
gage and the directional gyro.
The switch contacts
rotor.
Protect pump mounting flange with soft
are normally closed. The light may be checked by
metal or wood.
NEVER install a pump that
turning ON the master switch.
With the engine
has been dropped.
running the light should illuminate when the vacuum
drops below 3 ±. 5 inches Hg.
NOTE
15-30.
VACUUM RELIEF VALVE ADJUSTMENT.
Do not use teflon tape. pipe dope, or thread
A suction gage reading of 5. 3 inches of mercury is
lubricants of any type, and avoid over-
tightening of connections.
adjust relief valve. remove central air filter, run
d.
Install elbow in pump; hand-tighten only,
engine to 1900 rpm on ground and adjust relief valve
to 5. 3 ± . 1 inches of mercury.
NOTE
Use only a box wrench to tighten fittings to
Do not exceed maximum engine temperature.
Do not exceed maximum engine temperature.
desired position. Do not make more than
one and one half (1-1/2) turns beyond hand-
tighteand
posit
half
NOTE
Before installing vacuum pump on engine,
ensure that mating surfaces are clean and
free of any old gasket material.
15-17
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