Mooney M20B - Page 88

INSTRUMENT
TROUBLESHOOTING
(Continued)
*d
ENGINE
OIL PRESSURE
GAGE
Excessive
error
at
zero.
I
Pointer
loose
on
shaft.
Replace
instrument.
Overpressure
or
seasoni
ing
of
bourdon
tube.
Excessive
scale
error
Improper
calibration
Replace
instrument.
adj~tment.
Excessive
pointer Improper
damping
or
Disconn=ct;ine
and drain.
Check
frc;
oscillation
rough
relief
valve,
hal~.
1l
trouble
persists,
clean
and
adjust
relief
valve.
Sluggish
operation
of
Relief
valve
open.
Check
and
clean.
pointer
or
pressure
fails
to
build
up.
DIRECTIONAL GYRO
INDICATOR
(if
installed)
Excessive drift
in
either
Excessive vibration
with
Check shock
mounts.
di~ction.
amplitude
more
than
.006~
Insufficient
vacuum
If
Check
vacuum
vacuum
below
3.15 inches
a
Adjust.
Hg,
check
for the
b.
Recalibrate.
ing:
c.
Repair
or
replace
a
Relief valve
improperly
d.
Check
and
repair.
Check
for
adjusted.
collapsed
inner
wall of
hose.
b. Incorrect
gage
reading.
c
Pump
failure.
d.vacuum
line
kinked
or
leaking.
Def?ctive
instnunent:
Replace
instrument.
Dial
spins continuously.
Defective
mechanism,
I
Replace
instrument
HORIZON
INDICATOR
(if
installed)
Bar fails
to
respond.
Insufficient
vaniua
Check
pump
and
tubing.
Bar does
not
settle;
1
Excessive
vibration
Check
shock
mounts.
Replace
if
necessary.
Insufficient
vacuum, Check line
and
pump.
Adjust
valve.
Defective
instnunent.‘
.Replace.
Bar
oscillates
or
shimmies
Excessive
vibration.
Check
shock
mounts.
Replace
if
continuously.
necessary.
Vacuum
too
high.
I
A(ijustvalve
:´•wz~
Defective
mechanism
I
Repiaceinstrrlment.
t~’
.9,
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rt~
OLDWILLWAYNE