Evacuating Complete System - Pontiac Grand Prix Service Manual

CUSTOM AIR CONDITIONING 1A-3
CoMmEssoR
PILOT OPERATED ABSOLUTE
................................
................................
................................
................................
................................
..............................
..............................
FROM RECEIVER DEHYDRATOR
1.5421
A
Fig.
1A-2
Schematic
-
Evacuating Refrigerant System
a. Close hand shut-off valves on gauge set by turning pressure build-up escape completely. Close high pres-
clockwise. sure valve.
b. Remove caps from gauge fittings on P.O.A. valve
and compressor.
c. Attach Schrader valve adapter J 5420 to end of hose
from low pressure gauge and connect this adapter
fitted hose to suction gauge fitting.
d. Attach Schrader valve adapter J 6163 to end of hose
from high pressure guage and connect this adapter
fitted hose to discharge gauge fitting.
3. Check oil level in vacuum pump and add Frigidaire
150 viscosity oil or equivalent, if necessary, to bring to
proper level. Make sure dust cap on discharge side of
vacuum pump has been removed.
4. Start the vacuum pump and slowly open low and
high pressure sides of manifold gauge set to avoid
forcing oil out of refrigeration system and the pump.
Pressure is now being reduced on both sides of
refrigeration system.
3. Attach a flexible gauge hose to center fitting of the
NOTE:
oil
is
blown from vacuum pump,
it
be
gauge
set and attach the other end of this hose to the
relflled to the proper level with Frigidaire 150 viscosity
vacuum pump J 5428 or J 5428-01 (Fig. 1A-2).
oil or equivalent.
4. The system can now be evacuated.
5. Observe low pressure gauge and operate vacuum
pump until gauge shows 26-28" vacuum. Continue to
run pump for ten additional minutes.
EVACUATING COMPLETE SYSTEM
NOTE: In all evacuating procedures specification of
26-28 inches of vacuum is used. This evacuation can
1.
Turn
hand shut-off valve on low pressure gauge of
only be attained at or near sea level. For each 1000 feet
gauge set to full clockwise position.
above sea level where this operation is being performed,
specifcation should be lowered by one inch of mercury
2. Slowly turn valve on high pressure gauge counter- vacuum. For example: at 5000 feet elevation only 21 to
clockwise from full clockwise position, letting any 23 inches of vacuum can normally be obtained. If