Mooney M20K - Vacuum Regulator

MOONEY AIRCRAFT
CORPORATION
M20K
SERVICE
AND
MAINTENANCE
MANUAL
2.
Dry
air
pump
fittings.
Before
washing engine
off,
When
hose
clearance
is
tight,
making
it
difficult
to
check
pump
fittings
for
looseness
of
threaded
fittings.
reinstall
onto
pump
fitting,
spray
fitting
at
hose end
Fluid
can
seep
through
loose threads
and
enter
pump.
with
silicone.
LET
DRY,
then
install
hose
by pushing
it
3.
Dry
air
pump
discharge
hose
(vacuum
instrument
straight
on.
system)
Plug
end of
the
hose
or
fitting
and
flag
it
with
a
CAUTION
red
"Remove
Before
Running Engine"
tag,
then clean
engine.
Do
not
wiggle
hose
from side
to
side.
Wiggling
could
cause
particles
to
be
cut
from
hose
ID.
CAUTION
These
particles
would
damage
the
pump.
Remove
plug
prior
to
running engine.
CAUTION
37-11-02
SERVICING
Change
all filters
in
the
system.
This
must
be done
or
pump
wananty
may
be voided.
The
dry
air
pump
requires
no
servicing.
The intemal
parts
are
self-lubricating
and
require
NO
ADDITIONAL
37-12-00
-VACUUM
REGULATOR
lubricating.
The
vacuum
regulator
(2) (Figure
37-1)
is
a
spring-con-
37-11-03
-REMOVAL
trolled
diaphragm
valve for
regulating
vacuum
for
aircraft
pneumatic
instrument
system.
The
vacuum
1,
Disconnect
hoses from
dry
air
pump.
regulator
is
located
on
left
firewall,
inside
cabin,
just
2,
Remove air
pump
from
engine
and discard old
under
glareshield. Adjust
vacuum
regulator
valve
ac-
mounting gasket
and
locking
hardware.
cording
to
Section
37-12-05.
3,
Remove
fittings
from
pump.
Retain
fittings
a
they
are
serviceable;
clean
thoroughly
before
re-using.
Dis-
37-12-01
MAINTENANCE
PRACTICES
card twisted
fittings
and
nuts
with
rounded
corners.
Check
general
condition of
regulator
to
insure
it is
4.
Pad
inspection.
Check
condition of AND
20000
secure
and
in
airworthy
condition.
pad
seal,
If seal
shows
any
signs
of oil
leakage,
replace
seal.
Replace
seal If there is
any
doubt
as
to
its
serv-
37-12-02
SERVICING
iceability.
No
servicing
is
required
to
the
regulator
other
than
fil-
37-11-04
INSTALLATION OF
NEW
PUMP
ter
replacement.
See Section
37-13-00
for details.
37-1;-03
-REMOVAL
CAUTION
Never install
a
pump
that has been
dropped.
1. Undemeath
instrument
panel,
remove
both instru-
ment
lines
from
vacuum
regulator;
cap
to
prevent
1.
Consult
airframe
manufacturer’s
current
parts
foreign
objects
from
entering
them.
manual,
Airborne’s
Application
List,
or
PMA
label
on
2.
Engine
compartment,
remove
hose
from
vacuum
the
pump
box
to
verify
that the
pump
is
correct
model
regulator;
cap
to
prevent
foreign objects
from
entering.
for
engine
and/or
system.
3.
Loosen and
remove
large
nut
at
firewall
on
2.
Place
pump
mounting Range
in
a
jaw-protected
vacuum
regulator.
vise,
with drive
coupling
downward.
Protect
pump
4.
Pull
regulator
aft
to
remove
from aircraft.
mounting
Range
with soft metal
or
wood.
37-12-04
REINSTALL
CAUTION
1.
Inside
aircraft,
insert
vacuum
regulator
thru
Pump
housing
should
never
be
placed
directly
in
a
mounting
hole
in
firewall.
vise,
since
clamping
across
center
housing
will
2.
Install
large
nut
on
regulator
and
tighten.
cause
an
internal failure of carbon
rotor.
3.
Engine
compartment,
install
hose
from
pump
to
regulator
and
secure.
3.
Spray
fitting
thread
with silicone
and
LET DRY.
4.
Inside
aircraft,
install both
instrument
lines to
DO
NOT
use
teflon
tape,
pipe dope
or
thread
lube.
regulator
and
secure.
4.
Install
fittings
in
pump.
Hand
tighten.
5.
Use
only
a
box wrench
to
tighten fittings
to
37-12-05
-ADJUSTMENT
desired
position.
DO
NOT
make
more
than
one
and
1.
Tee
a
calibrated
vacuum
gauge
into
system
one
half
(1
1/2)
turns
beyond
hand-tight position,
upstream
of
regulator,
(see
Figure
37-1).
6. Install
new
pump
mounting
gasket
(supplied
with
2.
Operate
engine
at
a
minimum of
1700
engine
new
pump).
RPM.
If
vacuum
regulator
is
not
set at
4.75 0.25
In.
7.
Always
replace
ALL
locking
washers when install-
Hg.,
then bend
locking
tab
away
from thumb
adjust-
ing
a
new
pump.
Tighten
all
four
(4)
mounting
nuts
90
ment
screw.
Tuming
screw
in,
will
increase
vacuum;
to
110
in. Ibs.
tuming
screw
out,
will
decrease
vacuum.
Set
vacuum
3. Prior
to
reconnecting
hoses,
inspect
inside of the
to
read
4.75
t-/-.25
In.
Hg.
hose
carefully
to make
sure
it is clean and free
of all
debris,
oils
or
solvents.
Use
vacuum or
air
pressure
to NOTE
clean
lines.
Remove
hoses from the aircraft
if
neces-
After
setting regulator,
re-bend
tab back
to
lock
sary.
adjusting
screw.
37-11-02
OLDWILLWAYNE