Servicing The Alc System - Winnebago 1987-1989 LeSharo Service Manual

SERVICING THE AlC SYSTEM
STABILIZING THE SYSTEM
With Manifold Gauge Set connected into the
system, air and moisture purged from high and low
side test hoses, and both manifold hand valves
closed, the air conditioner is ready for testing. The
system must be operated for a few minutes to
allow all components to attain operating stability
and the system must be checked for a full
refrigerant charge before tests can be made.
Stabilize the system as follows:
System must be properly stabilized.
System Stabilizing Procedure
1. Start engine and adjust engine to normal fast
idle speed.
2. Turn air conditioner on and set for maximum
cooling with blower fan on high speed.
3. Open doors or windows.
4. Operate air conditioner for 5-10 minutes to
stabilize system.
5. Check system for full refrigerant charge by
noting sight glass indication. See page N3-4
for sight glass data. On systems where sight
glass is not used, note gauge readings. See
N4-3 for normal gauge readings. An
insufficient charge will be indicated by high
and low gauges registering lower than
normal.
System must have full charge.
If an insufficient refrigerant charge is indicated by
the test gauge readings and sight glass indication,
the system must first be fully charged before
accurate tests can be performed to determine the
cause of system failure. The stabilizing period is an
ideal time to add refrigerant to bring the system to
a full charge. Refer to ADDING REFRIGERANT.
Some refrigerant loss is normal.
Some refrigerant loss will occur from one season to
the next and is accepted as normal. Vibration, hose
porosity, and the general construction of
components mounted on a moving vehicle make
the leak-free system an exception. Replacing this
refrigerant loss between seasons will constitute
much of the quick service required on air
conditioning equipment.
ADDING REFRIGERANT
System must contain full refrigerant charge.
The air conditioner must contain a full refrigerant
charge before an accurate system check can be
made. An insufficient charge is indicated by both
the high and low side gauge readings registering
lower than normal. Also the sight glass will show a
stream of bubbles or foam. Refer to the
accompanying illustration and proceed as follows
with the system still in operation.
Adding Refrigerant Procedure
1. If can of refrigerant-12 is not already
connected to manifold gauge set center hose,
connect can as follows: Install can valve on can
of R-12 and connect can valve to center hose.
2. Loosen center hose connection at gauge
manifold, open can valve for several seconds to
purge air from the center hose, then tighten
hose connection and close can valve.
3. Start engine and operate air conditioner. With
system operating, slowly open low side
manifold hand valve to allow refrigerant to
enter the system.
NOTE The low side of the system is the SUCTION
side and the Compressor will pull
refrigerant from the can into the system.
Add charge on Low Side Only.
CAUTION
High side hand valve must never be opened while
system is operating. This would result in
refrigerant being pumped into the can and
causing it to burst. NOTE: The high side of the
system is the DISCHARGE side and compressor
would push refrigerant out of the system (unless
safety can valve used).
4. With refrigerant container in upright vapor
position, add refrigerant until sight glass clears
or gauge readings are normal.
NOTE Refrigerant can may be rocked from side to
side to increase flow of refrigerant into
system.
CAUTION
Never turn can into a position where liquid
refrigerant will flow into system.
5. Close low side manifold hand valve and
refrigerant can valve.
6. Continue to stabilize system and check for
normal refrigerant charge.
N3-1
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