Winnebago 1987-1989 LeSharo Service Manual page 614

DIAGNOSIS OF Ale SYSTEM
CONDITION 5
CONDENSER MALFUNCTION OR SYSTEM OVERCHARGE
LOW SIDE HIGH
lOW SIDE
HAND VALVE
CLOSED
LOW SIDE HOSE
CONNECTED TO
lOW SIDE SERVICE
CONNECTOR
JAMBIENT '
"!TEMP
.:95°'f-,
HIGH SIDE HIGH
HIGH SIDE
HAND VALVE
CLOSED
HIGH SIDE HOSE
CONNECTED TO
HIGH SIDE SERVICE
CONNECTOR
-I
,f
Complaint
Little or no cooling. Engine overheating may also
be noted.
Condition
1. Low side gauge reading excessively high.
Should be 15-30 psi.
2. High side gauge reading excessively high.
Should be 185-205 psi at 95°F. See chart for
pressures at other ambient temperatures.
3. Bubbles may appear occasionally in sight glass.
Liquid line very hot.
4. Discharge air from evaporator is warm.
Diagnosis
Improper condenser operation with lack of cooling
caused by excessivehigh side pressure. System may
have either normal charge or overcharge of
refrigerant.
Correction
1. Check for loose or worn drive belts causing
excessive compressor head pressures.
2. Inspect condenser for clogged air passages,
bug screen, or other obstructions preventing
air flow through condenser.
3. Inspect condenser mounting for proper
radiator clearance.
4. Inspect clutch type fan for proper operation.
5. Inspect radiator pressure cap for correct type
and proper operation.
After making above corrections:
1. Operate system and check performance.
If condition not corrected:
1. Inspect system for overcharge of refrigerant
and correct as follows:
a. Discharge refrigerant until stream of
bubbles appears in sight glass and both
high and low gauge readings drop below
normal.
b. Add new Refrigerant-12 until bubbles
disappear and pressures are normal, then
add 1/4-1/2 lb. more refrigerant.
2. Operate system and check performance.
If gauge readings still too high:
1. Discharge system.
2. Remove and inspect condenser for oil
clogging.
3. Replace Receiver-Drier.
4. Evacuate system using vacuum pump.
5. Charge system with NEW Refrigerant-12.
6. Operate system and check performance.
N4-8
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