R-4 Air Conditioning Compressor; General Description - Chevrolet 1991 Light Duty Truck Repair Manual

R-4 AIR CONDITIONING COMPRESSOR

NOTICE: When fasteners are removed, always reinstall them at the same location from which they were
removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If
the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be
used. Fasteners that are not reused, and those requiring thread locking compound will be called out. The
correct torque value must be used when installing fasteners that require it. If the above conditions are not
followed, parts or system damage could result.
SUBJECT
General D escription.....................................................................................................................................................1B3-1
Minor Repair to the Com pressor............................................................................................................................. 1B3-2
Clutch Plate and Hub A ssem bly.......................................................................................................................... 1B3-3
Clutch Rotor and Bearing: V-Groove Type........................................................................................................ 1B3-4
Clutch Rotor and Bearing: Poly-Groove Type...................................................................................................1B3-6
Clutch Coil And/Or Pulley Rim Replacement: V-Groove Type..................................................................... 1B3-8
Clutch Coil And/Or Pulley Rim Replacement: Poly-Groove Type................................................................ 1B3-8
Major Repair to the Com pressor............................................................................................................................. 1B3-9
Shaft Seal Replacement......................................................................................................................................... 1B3-9
Pressure Relief \telve Replacement...................................... ............................................................................ 1B3-11
High Side High Pressure Cutoff S w itc h .......................................................................................................... 1B3-11
Front Head and O-Ring Replacement.............................................................................................................. 1B3-11
Leak Te sting ............................................................................................................................................................1B3-12
Specifications ........................................................................................................................................................... 1B3-13
Special Tools.............................................................................................................................................................. 1B3-14
The Harrison R-4 compressor is a four cylinder, radial
opposed with 10.0 cubic-inch displacement.
There are two designs of the clutch driver which
affect the overhaul procedure. The four pole clutch and
the six pole clutch (figures 1 and 2). There are also two
types of pulleys used with the R-4 which also affect
some procedures.
When servicing the compressor, it is essential that
steps be taken to prevent dirt or foreign material from
getting on or into the compressor parts and system
during disassembly or assembly. Clean tools and clean
work area are very important for proper service. The
compressor connection areas and the exterior of the
compressor should be cleaned off as much as possible
prior to any repairs. Parts must be kept clean at all
times and any parts to be reassembled should be
cleaned with trichlorethane, naphtha, Stoddard solvent,
R-4 AIR CONDITIONING COMPRESSOR 1B3-1
SECTION 1B3
CONTENTS

GENERAL DESCRIPTION

kerosene or equivalent solvent and blown dry with dry
air. When necessary to use a cloth on any part, it
should be of a nonlint producing type.
Although certain service operations can be per­
formed without removing the compressor from the vehi­
cle, the operations described here are based on bench
repair with the compressor removed from the vehicle.
They have been prepared in sequence in order of
accessibility of the components (figure 3).
When the compressor is removed from the vehicle
the oil in the compressor must be drained and mea­
sured. The oil should then be discarded. If less than
29.5 ml (1 fl. oz.) is drained from the compressor add
59 ml (2 fl. oz.) of new 525 viscosity oil to the assembly
after overhaul. If more than 29.5 ml (1 fl. oz.) is drained
from the compressor, add the same amount of new 525
viscosity oil to the overhauled assembly.
PAGE