GMC 1989 Light Duty Truck Repair Manual page 77

HR-6 AIR CONDITIONING COMPRESSOR
SUBJECT
D es crip tio n .....................................................................................................................................................................................
Minor Repair to the C o m p re s s o r..............................................................................................................................................1B4- 2
Clutch Plate and Hub Assembly Replacem ent.................................................................................................................. 1B4- 2
Pulley and Bearing Assembly R e p la c e m e n t.....................................................................................................................
Clutch Coil and Housing Assembly R ep lacem en t............................................................................................................1B4- 7
Major Repair to the C o m p re s s o r..............................................................................................................................................1B4-
Shaft Seal R ep la ce m e n t.........................................................................................................................................................
High Pressure Relief Valve R eplacem ent............................................................................................................................
Compressor Disassembly- Internal Cylinder and S h a ft................................................................................................
Compressor Assem bly- Internal Cylinder and S h a f t .....................................................................................................1B4-12
Leak T e s tin g .................................................................................................................................................................................. 1B4-15
Specifications................................................................................................................................................................................ 1B4-16
Special Tools.................................................................................................................................................................................. 1B4-17
The Harrison HR-6 com pressor is a fixed displacem ent
axial piston pum p, w ith th re e dou ble-e nd ed piston s
actuated by an axial (swash) plate shaft assembly (figure 1).
The main parts are the front and rear cylinder, the shaft and
axial swash plate, piston group, and valve mechanisms.
The cylinders and heads provide an integral external shell.
The piston group of the com pressor is not serviceable. If
piston, bearing, ball shoe, shaft and axial plate, or cylinder
repair is needed, replace the internal cylinder assembly. All
clutch parts, valve mechanisms, and head assemblies are
serviceable, plus seals and gaskets.
Refrigerant oil, dispersed in the refrigerant vapor, lubri­
cates the system.
The front head is shown with three integral mounting
flange ears (figure 2). These ears have 19 mm flats cast to
provide for a wrench to be used as a prying means when
tensioning the compressor drive belt.
There are two clutch driver designs for the HR-6 com ­
pressor: The clutch driver w ithout a torque cushion and the
clutch driver having a thin torque cushion (figures 3 and 4).
Note: When servicing clutch drivers with a torque cushion,
the clutch hub holding tool J 25030 is used in place of
J 33027.
Keep dirt or foreign material from getting on or into the
compressor parts and system. Keep the work area and
tools clean.
HR-6 AIR CONDITIONING COMPRESSOR 1B4-1
SECTION 1B4
CONTENTS
DESCRIPTION
with Trichloroethane, naphtha, Stoddard sovlent, kerosene
or equivalent solvent and dry with dry air. Use only lint free
cloths to wipe parts.
overhaul with the com pressor removed from the truck,
except as noted. They have been prepared in order of
accessibility of the components. When a com pressor is
removed from the truck for servicing, the amount of oil
remaining in the compressor should be drained, measured
and recorded. This oil should then be discarded and an
equal amount of new 525 viscosity refrigerant oil added to
the compressor.
Note: The service com pressor is shipped with 8 oz. of 525
viscosity refrigerant oil. This oil should be drained and
retained for replacem ent oil when service procedures
require addition of new oil to compressor.
without discharging the system. Major repair procedures
require that the system be discharged of refrigerant.
IDENTIFICATION
vides the name of the manufacturer, model num ber and
build code. If the label is removed or becomes dislodged
during service operation, reattach it using an adhesive
sealant such as Loctite 312 or equivalent.
Keep the parts clean at all times. Clean assembled parts
The operations described below are based on bench
Most minor repair procedures may be done on the truck
An identification label attached to the com pressor pro­
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