Cessna 182 1978 - Dampening Screw Adjustment; Engine Indicators; Manifold Pressure Gage; Tachometer

MODEL
182 & T182 SERIES
SERVICE MANUAL
15-31.
ENGINE
INDICATORS.
15-34.
MANIFOLD
PRESSURE
GAGE
- 182.
15-32.
TACHOMETER.
15-35.
DESCRIPTION.
The manifold
pressure
gage
is a barometric
instrument which
indicates absolute
15-33.
DESCRIPTION.
The tachometer
is a me-
pressure
in the
intake manifold
in inches
of mercury.
chanical
indicator driven at
half crankshaft speed
by
a
flexible
shaft. Most
tachometer
difficulties
will
15-35A.
DAMPENING
SCREW
ADJUSTMENT.
be found
in the
drive-shaft.
To
function
properly,
If sluggish
or excessive
vibration
of the needle
the shaft
housing
must be
free of
kinks, dents
and
is noted,
check the
adjustment
of the
screw
as
sharp
bends. There
should
be no bend
on a radius
follows:
Evacuate
the instrument
to
10 in. Hg.,
shorter than
six inches
and no bend
within three
release
the vacuum
abruptly,
and check the
time
inches
of either
terminal.
If a tachometer
is
noisy
required
for
the needle
to pass
from 10
in. Hg.
or the pointer
oscillates,
check cable
housing
for
to
25 in. Hg.
The
required
time should
check
kinks,
sharp bends
and
damage.
Disconnect
cable
2 seconds
± 1.0 second.
Refer
to
paragraph
at tachometer
and pull
it out of housing.
Check cable
15-38 for
additional
trouble
shooting
information.
for worn
spots, breaks
and kinks.
15-36. MANIFOLD
PRESSURE/FUEL
PRESSURE
NOTE
GAGE - T182.
Before
replacing a tachometer cable in hous-
15-37. DESCRIPTION. The manifold
pressure and
ing,
coat lower two
thirds with AC
Type ST-
fuel pressure
gage are in
one instrument
case. How-
640 speedometer cable grease or
Lubriplate ever, each instrument
operates independently. The
No. 110. Insert
cable in housing
as far as
manifold pressure gage
is a barometric instrument
possible,
then slowly
rotate to make
sure it
which indicates
absolute
pressure in the
intake man-
is seated in the engine fitting.
Insert cable in ifold in inches of mercury.
The fuel pressure gage
tachometer, making
sure it is seated in drive
is a pressure
instrument calibrated
in PSI indicating
shaft, then reconnect
housing and hand
tighten, approximate
fuel pressure
to the engine. Pressure
then torque 1/4 turn.
for operating
the indicator is obtained through a hose
from
the fuel
manifold valve.
15-38. TROUBLE
SHOOTING - MANIFOLD
PRESSURE GAGE.
TROUBLE
PROBABLE
CAUSE
REMEDY
EXCESSIVE
ERROR AT
Pointer
shifted.
Replace
instrument.
EXISTING BAROMETRIC
PRESSURE.
Leak in
vacuum
bellows.
Replace
instrument.
Loose pointer.
Replace instrument.
Leak
in pressure
line.
Test line
and connections
for
leaks.
Repair
or
replace
damaged
line,
tighten
connections.
Condensate or fuel in line.
Check line for
obstructions.
Blow
out line.
JERKY MOVEMENT
OF
Excessive
internal
friction.
Replace
instrument.
POINTER.
Rocker
shaft
screws tight.
Replace
instrument.
Link springs
too tight.
Replace
instrument.
Dirty
pivot bearings.
Replace
instrument.
Defective
mechanism.
Replace
instrument.
Leak in pressure
line.
Test
line and connections
for leaks.
Repair
or replace
damaged line.
tighten
connections.
15-18C/(15-18D
blank)