Section 22: HEATING AND AIR CONDITIONING
PA1562
15
6.2.4 Precautions in Handling Refrigerant
Lines
1. All metal tubing lines should be free of
kinks, because of the resulting restrictions
on the flow of refrigerant. A single kink can
greatly reduced the refrigeration capacity of
the entire system.
2. The flexible hose lines should never be
allowed to come within a distance of 2-½"
(6,3 cm) from the exhaust manifold.
3. Use only sealed lines from parts stock.
4. When disconnecting any fitting in the
refrigeration system, the system must first
be discharged of all refrigerant. However,
proceed very cautiously, regardless of
gauge readings. If there happens to be
liquid refrigerant in the line, disconnect
fittings very slowly, keeping face and hands
away so that no injury can occur. If pressure
is noticed when fitting is loosened, allow it
to bleed off very slowly.
WARNING
Always wear safety goggles when opening
refrigerant lines.
5. In the event that any line is opened to the
atmosphere, it should be immediately
capped to prevent entrance of moisture and
dirt.
6. The use of the proper wrenches when
making connections on O-ring fittings is
important. The use of improper wrenches
may damage the connection. The opposing
fitting should always be backed up with a
wrench to prevent distortion of connection
lines or components. When connecting the
flexible hose connections, it is important
that the swaged fitting and the flare nut, as
well as the coupling to which it is attached,
be held at the same time using three
different wrenches to prevent turning the
fitting and damaging the ground seat.
7. The O-rings and seats must be in perfect
condition. The slightest burr or piece of dirt
may cause a leak.
8. O-rings should be coated with refrigeration
oil and installed on the line before the line is
inserted into the fitting to prevent damaging
the O-ring. If leaks are encountered at the
couplings or connectors, no attempt should
be made to correct the leaks by tightening
the connections beyond the recommended
torque. The O-rings are designed to seal at
the specified torque and overtightening the
connection does not result in a satisfactory
and permanently sealed connection. The
connection must be disassembled and the
cause of the leak (damaged O-ring,
defective lines, etc.) corrected. Use new
O-ring.
6.2.5 Auxiliary System Refrigerant Lines
1. From the inside of the coach, remove the
mirror located inside the lavatory to access
the Y connector separating the system two
sides. Also a small access panel located in
front of the lavatory entrance door, near the
ceiling enables to reach the R.H. side supply
and return line fittings.
2. The L.H. side supply and return line fittings
are accessible by removing the rearmost
overhead storage compartment separator.
6.3 PUMPING DOWN
This procedure is intended to reduce refrigerant
loss, on central system only, by isolating it in the
compressor and the receiver tank, as well as in
their connecting line, in order to carry out repairs
on other sections of the air conditioning system
(lines and components).
NOTE
Before attempting any repair between
compressor and receiver tank, use a recovery
unit to remove refrigerant from the system.
NOTE
On vehicles equipped with an auxiliary A/C
system, refer to “Sanden SD7 Service Manual".
WARNING
To prevent any injury, when air conditioning
system must be opened, refer to previous
paragraph “PRECAUTIONS IN HANDLING
REFRIGERANT”.
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