GMC 1990 Light Truck Repair Manual page 95

SD-709 AIR CONDITIONING
SUBJECT
Description................................................................................................................................................................... 1B5-1
Inspection..................................................................................................................................................................... 1B5-1
Compressor Replacem ent.......................................................................................................................................... 1B5-1
Disassembly of the Clutch and Shaft S eal.................................................................................................................1B5-1
Assembly of the Clutch and Shaft S e a l..................................................................................................................... 1B5-4
Disassembly of the Cylinder Head and Valve Plate.................................................................................................. 1B5-6
Assembly of the Cylinder Head and Valve P la te ...................................................................................................... 1B5-6
Specifications................................................................................................................................................................... 1B5-7
Fasteners......................................................................................................................................................................... 1B5-7
Special Tools..................................................................................................................................................................... 1B5-8
DESCRIPTION
The Sandon SD-709 is a belt-driven seven cylinder com­
pressor with an integral clutch. The clutch, shaft seal, cylin­
der head and valve plate assemblies are fully serviceable.
The compressor can be identified by a label attached to
the compressor body giving the part number, model, and
manufacturer's name. The date code is stamped on the
front left mounting ear viewed as facing the clutch (figure 1).
It will be either a two-digit number or a number-letter combi­
n a tio n . T h e firs t n u m b e r g iv e s th e y e a r o f m a n u fa c tu re .
This is followed by one of the numbers 1 through 9, indica­
ting the months January through September. October,
November or December are indicated by an X, Y, or Z.
INSPECTION
LEAK CHECK
Before disassembling any compressor components,
check for leaks in the following areas:
1. Feel under the seal area between the clutch and com­
pressor to check for oil seeping in the shaft seal area.
If so, the seal will have to be replaced.
2. Check for dislocation of the front housing O-ring (pro­
truding section). Replace the compressor.
3. Oil around the cylinder head gasket or fittings.
Replace leaking component.
4. Oil around the filler hole. If the O-ring is damaged, it
can be replaced. If the threads are stripped, replace
the compressor.
SD-709 AIR CONDITIONING COMPRESSOR 1B5-1
SECTION 1B5
COMPRESSOR
CONTENTS
5. Oil leaking from cracks in the cylinder block. Replace
the compressor.
COMPRESSOR REPLACEMENT
If the compressor needs to be replaced, first drain and
measure the oil in the old compressor. Then drain the oil
from the new compressor. Measure the new oil equal to the
amount drained from the old compressor. Then put the new
oil back in the compressor.
DISASSEMBLY OF THE
CLUTCH AND SHAFT SEAL
CLUTCH
Remove or Disconnect (Figures 2 through 9)
Tools Required:
J 37791 Clutch Front Plate Spanner Wrench
J 36045 Front Plate Puller
J 37792 Puller Fingers
J 8433 Puller Set
J 37795 Bearing Remover and Installer/Pulley
Installer
J 29886 Driver Handle
Insert the two pins of the J 37791 into any two
threaded holes of the clutch front plate (2). Hold the
clutch plate stationary (figure 3).
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