GMC chervolet camaro 1999 Service Manual page 215

1-124 HVAC System - Manual
Handling of Refrigerant Lines and Fittings
• Ensure that the metal lines do not exhibit the
following conditions.
This will prevent the loss of system capacity due
to line restriction:
- Dents
- Kinks
• Do not bend the flexible hose line to a radius of
less that 4 time the diameter of the hose.
• Do not allow the flexible hose line to come within
a distance of 63.5 mm (2 V2 in) of the exhaust
manifold.
• Inspect the flexible hose lines regularly.
Replace the flexible hose line with new hose if
one of the following conditions exist:
- Leaks
- Brittleness
- Deterioration
• Before disconnecting any fitting in the refrigeration
system, discharge all of the Refrigerant-134a.
Refer to Refrigerant Recovery and Recharging.
• Once you open a refrigerant line to the
atmosphere, cap or tape the line immediately.
This will prevent any of the following items from
entering the line:
- Moisture
- Dirt
• Use the proper wrenches when you make
connections on the 0-ring fittings.
Back-up the opposing fitting with a wrench in
order to prevent distortion of the following areas:
- The connecting lines
- The components
• Tighten all of the tubing connections to the
specified torque.
Too much or too little torque may result in the
following conditions:
- loose joints
- Deformed joint parts
- Refrigerant leakage
- An inoperative A/C system
• Ensure that the 0-rings and the seats are in
perfect condition. ·
A burr or a piece of dirt may cause a
refrigerant leak.
• Install new 0-rings that you have lubricated with
the mineral base 525 viscosity refrigerant oil.
Do not use polyalkylene glycol (PAG) synthetic oil.
Do not wipe the threads with a cloth.
• Keep PAG synthetic refrigerant oil off fitting
threads. Long term contact of PAG synthetic oil on
threads may cause future disassembly difficulties.
Flush threads of fitting with mineral base
525 viscosity refrigerant oil. Do not use PAG
synthetic oil. Do not wipe threads with a cloth.
HVAC
Maintaining Chemical Stability
The chemical stability of the refrigeration system plays (
an important role in the efficient operation and
longevity of the A/C system.
When air, moisture or particulate contamination are
introduced into the refrigeration system, the following
results will occur:
• The chemical stability of R-134a and polyalkylene
glycol (PAG) synthetic lubricant will change.
• The pressure/temperature symmetry will change.
• The A/C system efficiency will be diminished.
• Internal A/C system parts may corrode and/or
wear in an abnormal manner.
Use the following general practices to maintain
chemical stability in the refrigeration system:
• Wipe away dirt and/or oil before you break a
refrigerant connection. This will reduce the
possibility of particulate contamination.
• Cap, plug or tape both sides of an open
connection as soon as possible. This will minimize
the amount of dirt and moisture entering the
system.
• Ensure that the following remain clean and dry:
- The tools being used for the repair
- The surrounding area of the repair
- The hoses and connectors for the ACR4
machine or manifold gage set
- The replacement parts
• When ac::lding polyalkylene glycol (PAG) lubricant,
ensure the transfer device and the container
remain clean and dry to minimize moisture
intrusion.
• Do not leave the A/C system open any longer
than necessary.
• Before recharging an A/C system that has been
opened, properly evacuate and vacuum test
the system.
• Service parts are dehydrated and sealed prior to
shipping. Retain the parts in their sealed
packages until you are ready to use them.
• Ensure the parts are at room temperature before
opening the packages. This prevents condensation
on the parts from humidity in the atmosphere.
• Attach the A/C service equipment quick-connects
as soon as possible after removing the
service caps.
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