Chevrolet 1977 10 Series, Repair Manual, Page: 38 / 468

1B-32 OVERHAUL MANUAL
P IS T O N A N D
REED A SS E M B L Y
Fig. 9 4 —I nsta11ing Shell A s s e m b ly
Fig. 9 3 -- ln s p e c t in g Piston and Reed A s s e m b ly
rings and back against shell stop flange at the rear of
compressor cylinder.
If one screw appears to require more force to turn than
the other, immediately turn the other screw to bring the
screw threading sequence in step or the shell will be cocked
and made more difficult to install. Norm al installation does
not require m uch force on wrench if screws are kept in step
while turning.
8. When shell is seated against the stops, bend shell
retaining strap down into place by tapping gently with a
hammer.
9. Remove shell installing fixture J-25008-2 and leak
test compressor.
OIL CHARGE
The radial four cylinder com pressor is charged with 6.0
ounces of 525 viscosity oil. D uring norm al operation a
certain am ount of oil will circulate with the Refrigerant 12
(R-12) in the system.
W hen necessary to replace a system com ponent it is
recommended that oil be added to the system in accordance
to the following procedure.
If com pressor is operable, idle vehicle for 10 minutes
with the A /C controls set for M axim um Cooling and High
Blower prior to discharging the system.
A dd additional oil as indicated in Diagnosis Section of
this Service Manual.
Oil Charge-Compressor Replacement
1. G ravity drain oil from a new compressor.
Position com pressor with shaft end "up" and drain
com pressor suction and discharge ports. The compressor
should gravity drain for 10 minutes.
A dd additional oil as indicated in Section IB of the
Service Manual.
W hen necessary to flush system with R - ll, drain
assembly and blow dry with air prior to the installation of
a new compressor. It is not necessary to drain oil from the
replacement compressor.
2. The refrigerant 12 (R-12) is to be slowly discharged
from the system.
3. Remove original com pressor from vehicle, gravity
drain the oil from com pressor as in Step 1 and determine
the am ount of oil drained from the original compressor.
Refer to the oil usage chart in section IB of the Service
manual for proper am ount of oil to be added.
SYSTEM PERFORMANCE EVALUATION
When system performance, efficiency and proper oil
charge is in doubt and m ust be evaluated accurately, it is
recommended that the system be flushed with R - l l and the
exact oil charge (6 ounces) of 525 viscosity oil be added to
the com pressor prior to any further checks of the system.