Raytheon Beech Baron E55 - Page 462

Raytheon
nircraft
Company
BARON
55
AND
58
SHOP
MANUAL
fcnuTlhll
CAUTION
Insufficient
torque,
when
tightening
tubing
connections,
can
result in
loose
joints
and excessive
torque
can
result
in
deformedjointparts.
Either
condition
can
result
in
refrigerant
leakage.
Refer
to
Step
c.
for
correct
torque
values.
I
When
connecting
aluminum
fittings
in
the
refrigerant
system,
torque
all
5/8
in.
fittings
to
216 to
252
in.-lbs
and
all
1/2 in,
fittings
to
132
to
156
in.-lbs.
d. Use
refrigerant
R-12
(Item
34,
Consumable
Materials
Chart,
Section
2)
in
this
system
on
airplanes
TH-1
thru
I
TH-1744
or
R-134a
(Item
68,
Consumable
Materials
Chart)
on
airplanes
TH-1745
and
After.
Other
refrigerants.
particularly
those
containing methyl
chloride,
will
cause
rapid
deterioration
of
aluminum
components.
SYSTEI1II
LEAK
DETECTION
NOTE
It is
permissible
to
add
4
ounces
of
refrigerant
leak
detector
dye
(70,
Consumable
Materials
Chart,
Section
2),
to
the
suction
side of
the
refrigerant
system
to detect
leaks.
A
red
film
will
appear
in
the
areas
of
leakage.
A
reduction
of
system
cooling
ability,
or
the
presence
of bubbles
in
the
refrigerant,
may
indicate
a
partial
loss
of
refrigerant.
The
sight glass
should be
checked
during operation
at
maximum
available
ambient
and
cabin
temperature.
Streams
of
bubbles
past
the
glass
or
foam in
the
glass
indicates
an
inadequate
refrigerant
quantity.
If
a
loss
of
refrigerant
is
suspected,
an
inspection
of
the
system
plumbing
should
be
carried
out to
locate the
source
of
the leak.
Large
leaks
may
be located
by
the
appearance
of
oily
spots
where oil
has
been
carried
out
by
escaping
refrigerant.
Smaller
leaks,
which
are
much
more
difficult
to
locate,
may
be
detected
by
detergent
bubbles,
or
an
electronic
detector.
In
order
to
use
the
above
detectors,
the
system
must
contain
a
partial
charge
and be
operating.
The
detergent
test
is
accomplished
by
covering
a
suspected
area
with
soap
suds
and
watching
for
bubbles.
An
electronic detector
has
a
probe
which is
moved
along
the
plumbing
to
pick
up
escaping
refrigerant.
Refrigerant
is
heavier than
air
so
the
probe
should
be
held below
the
lines. Various
types
of
electronic
and
fluorescent
leak
detectors
are
available and each
type
operates
in
a
somewhat
different
manner.
The
detector
manufacturer’s
instructions
should be
reviewed for
proper
usage
of the
instrument.
If
a
leak
is
detected
at
a
fitting,
the
use
of
a
soft
copper
flare
gasket
in
the
flare
fitting
is
permissible
if
the
connection
does
not
seal
by
the
normal
method.
I
Any
leak
detected
with
soap
bubbles is
leaking
sufficiently
to
require
repair.
Electronic
detectors
are
very
sensitive
and
may
detect
leaks
that
are
small
enough
to
be
insignificant.
While
compressor
shaft
seals
should be
repaired
only
if
they
leak
more
than
0.5
ounce a
year,
any
other leak
exceeding
0.3
ounce
a
year
should
be
repaired.
Any
area
suspected
of
leaking
should be
cleaned
with
soap
and
water.
NOTE
I
A
useful device
may
be
made
of
a
1/4
in.
copper
tube
for
detecting
shaft
seal
leaks
on
an
installed
compressor.
Acquire
a
12
in.
long
tube
and
put
a
90"
bend
3/4 in.
from
the
end.
Insert
the
straight
end into
the
detector
hose
and
insert
the other
end into
one
of
the
holes
in
the
compressor
clutch
plate.
Jun
27/03Page
24
SECTION
10
E20