Buick LeSabre 1965 Service Manual page 842

ACCESSORIES
OPTIONAL HEATER-AIR CONDITIONER SYSTEM 1 1 - 1 0 9
COMPLAINT AND CAUSE CORRECTION
2. Compressor Discharge Pressure Too High
(a) Engine overheated
(b) Overcharge of refrigerant or oil in
system
(c) Restriction in condenser or receiver
liquid indicator
(d) Condenser air flow blocked
(e) Evaporator pressure too high
3. Compressor Discharge Pressure Too Low
(a) Insufficient refrigerant
(a) See Group 2 for possible cause.
(b) Systems with excess discharge pressures
should be slowly depressurized. (1) If dis-
charge pressure drops rapidly, it indicates
air (with possibility of moisture) in the sys-
tem. When pressure drop levels but still
indicates in excess of specifications shown
in the FUNCTIONAL TEST CHART, slowly
bleed system until bubbles appear in the
sight glass and stop. Add refrigerant until
bubbles clear, then add one-half pound of
refrigerant. Recheck operational pressures.
If system pressures still remain above
specifications, and the evaporator pressure
is slightly above normal, then a restriction
exists in the high pressure side of the sys-
tem. (2) If discharge pressure drops slowly,
it indicates excessive refrigerant. If pres-
sures drop to specifications and sight glass
remains clear, stop depressurizing and re-
check operational pressures. If pressures
are satisfactory, depressurize until bubbles
appear in the sight glass, stop depressuriz-
ing, then add one-half pound refrigerant.
Recheck operational pressures. (3) If dis-
charge pressure remains high after
depressurizing the system, continue de-
pressurizing until bubbles appear in the
sight glass. If evaporator pressures also
remain high, there is a possibility of a
restriction in the high pressure side of the
refrigeration system or the STV may re-
quire adjustment. See EVAPORATOR
PRESSURE TOO HIGH.
(c) Remove p a r t s , inspect, and clean or
replace.
(d) Clean condenser and radiator core sur-
faces as well as the space between the con-
denser and radiator.
(e) See EVAPORATOR PRESSURE TOO HIGH.
(a) Check for presence of bubbles or foam in
liquid indicator. If bubbles or foam are
noted (after five minutes of operation),
check system for leaks, if no leaks are
found refrigerant should be added until
sight glass clears, then add an additional
1/2 lb.