GMC 1989 Light Duty Truck Operating instructions

vr’V'-’
Light Duty Truck
Unit Repair Manual

FOREWORD
This manual includes procedures involved in disassembly and assembly of compo
nents listed in the “ Table of Contents.”
This manual should be kept in a handy place for ready reference. If properly used, it
ill meet the needs of technicians and vehicle o ners.
CAUTION
These vehicles contain some parts dimensioned in the metric system as ell as in the
customary system. Some fasteners are metric and are very close in dimension to famil
iar customary fasteners in the inch system. It is important to note that, during any vehicle
maintenance procedures, replacement fasteners must have the same measurements
and strength as those removed, hether metric or customary. (Numbers on the heads of
metric bolts and on surfaces of metric nuts indicate their strength. Customary bolts use
radial lines for this purpose, hile most customary nuts do not have strength markings.)
Mismatched or incorrect fasteners can result in vehicle damage or malfunction, or
possibly personal injury. Therefore, fasteners removed from the vehicle should be
saved for re-use in the same location henever possible. Where the fasteners are not
satisfactory for re-use, care should be taken to select a replacement that matches the
original. For information and assistance, see your authorized dealer.
No part of this publication may be reproduced, stored in
any retrieval system or transmitted, in any form or by any
means, including but not limited to electronic, mechani
cal, photocopying, recording or other ise, ithout the
prior ritten permission of the GMC Truck Division of
General Motors Corp. This includes all text, illustrations,
tables and charts.
GMC TRUCK DIVISION
TRUCK & BUS GROUP
General Motors Corporation
Pontiac, Michigan

To reduce the chance of personal injury and/or property damage, the
following instructions must be carefully observed.
Proper service and repair are important to the safety of the service tech
nician and the safe, reliable operation of all motor vehicles. If part replace
ment is necessary, the part must be replaced with one of the same part
number or with an equivalent part. Do not use a replacement part of lesser
quality.
The service procedures recommended and described in this service
manual are effective methods of performing service and repair. Some of
these procedures require the use of tools specially designed for the pur
pose.
Accordingly, anyone who intends to use a replacement part, service
procedure or tool, which is not recommended by the vehicle manufacturer,
must first determine that neither his safety nor the safe operation of the
vehicle will be jeopardized by the replacement part, service procedure or
tool selected.
It is important to note that this manual contains various Cautions and
Notices that must be carefully observed in order to reduce the risk of
personal injury during service or repair, or the possibility that improper
service or repair may damage the vehicle or render it unsafe. It is also
important to understand that these ‘Cautions’ and ‘Notices’ are not ex
haustive, because it is impossible to warn of all the possible hazardous
consequences that might result from failure to follow these instructions.
CAUTION

1989
UNIT REPAIR
MANUAL
COVERING
LIGHT DUTY
TRUCKS
The Table of Contents on this page indi
cates the sections covered in this manual.
At the beginning of each individual section
is a Table of Contents hich gives the
page number on hich each major subject
begins.
When reference is made in this manual
to a brand name, number, or specific tool,
an equivalent product may be used in
place of the recommended item.
All information, illustrations, and specifi
cations contained in this M anual are
based on the latest product information
available at the time of publication ap
proval. The right is reserved to make
changes at any time ithout notice.
X-8937
© 1988 General Motors Corporation June, 1988
Printed in USA.
All rights reserved.
TABLE OF CONTENTS
SEC. SECTION NAME
OA GENERAL INFORMATION
1AIR CONDITIONING
1B1 A6 Air Conditioning Compressor
1B2 V5 Air Conditioning Compressor
1B3 R-4 Air Conditioning Compressor
1B4 HR-6 Air Conditioning Compressor
1B5 SD-709 Air Conditioning Compressor
3STEERING
3B2 Manual Steering Gear
3B3 Power Steering
4AXLES
4B Rear Axle
4B1 7 1/2 Inch Ring Gear
4B2 8 1/2 Inch Ring Gear
4B3 9 1/2 Inch Ring Gear
4B4 10 1/2 Inch Ring Gear
4B5 Dana Rear Axles
4B6 12 Inch Ring Gear (Rockwell)
4B7 Locking Differentials
4C Front Axle
4C1 8 1/2 Inch Ring Gear
4C2 9 3/4 Inch Ring Gear
4C3 T Truck Front Axle
4C4 K Truck Front Axle 8 1 /4 and 9 1 /4 Inch
Ring Gear
5 BRAKES
6 ENGINE
6A General Engine
6A1 2.5 Liter L4
6A2 2.8 Liter V6
6A3 4.3 Liter V6
6A4 4.8 Liter L6
6A5 V8 Engine
6A7 6.2 Liter Diesel
6C Carburetor and TBI Unit
6C1 Model 1MEF Carburetor
6C2 Model M4MEF Carburetor
6C3 TBI Unit Model 220
6C4 TBI Unit Model 700
6D Engine Electrical
6D1 SI Series Generators
6D2 CS-144 Generator
6D3 SD (MT) Starting Motors
6D4 PG-200 (PMGR) Starting Motor
6D5 Distributors
7 TRANSMISSION
7A Automatic Transmission
7A1 700-R4 Automatic Transmission
7A2 400/475 Automatic Transmission
7A3 180C Automatic Transmission
7B Manual Transmission
7B1 HM-290 Manual Transmission
7B2 HM-117 Transmission
7B3 New Process Transmission
7B4 Borg-Warner Transmission
7D Transfer Case
7D1 New Process 205 Transfer Case
7D2 New Process 241 Transfer Case
7D3 New Process 231 Transfer Case
7D4 Borg Warner 1370 Transfer Case
f

No one
knows your
GIVI truck
better.
No one.
Mr. Goodwrench wants you to have the right parts for
your truck—whether you see him for service or whether
you do the work yourself.
That’s why Mr. Goodwrench wants to have a good
stock of genuine GM Parts availa le. Everything from
exclusive GM Goodwrench replacement engines and
transmissions to GM Goodwrench Motor Oil that meets
or exceeds all specifications for General Motors cars
or light trucks. And Mr. Goodwrench has a complete
line of GM chemicals for fine care of your GM vehicle.
Plus accessories to add convenience—
or just a little extra style.
So keep that great GM feeling with genuine GM parts
at participating independent Mr. Goodwrench dealers
selling Chevrolets, Pontiacs, Oldsmo iles, Buicks,
Cadillacs, GMC and Chevy Trucks.
GM QUALITY
SERVICE PARTS
Of NIRAL MOTORS CORPORATION
S
iv
F05085

SECTION OA
GENERAL INFORMATION
CONTENTS
SUBJECT PAGE
Service Parts Identification L a b e l.......................................................................................................................................OA- 1
Vehicle Identification Plate....................................................................................................................................................OA- 1
Certification Label....................................................................................................................................................................OA- 1
Engine Identification Number................................................................................................................................................OA- 2
Model Reference...................................................................................................................................................................... OA- 2
Metric Fasteners...................................................................................................................................................................... OA- 2
Fastener Strength Identification...........................................................................................................................................OA- 3
Six Lobed Socket Head Fasteners......................................................................................................................................OA- 4
Prevailing Torque Fasteners..................................................................................................................................................OA- 4
Conversion Table...................................................................................................................................................................... 0A-10
Decimal and Metric Equivalents...........................................................................................................................................OA-11
Service Parts Identification DO NOT REMOVE
1. VIN 6 5
2. W heel Base 5. R P O /SE O C odes
3. M odel N u m ber 6. Exterior C olor WA Nu m b ers
4. Order N u m ber 7. Paint S ystem F-0S40?
Figure 1—Service Parts Identification Label
SERVICE PARTS
IDENTIFICATION LABEL
The Truck Service Parts Identification Label is provided
on all models (figure 1). It is located on the inside of the
glove box door (or on an inner body panel for Forward
Control models). The Label lists the VIN (Vehicle
Identification Number), wheelbase, paint information and
all Production options or Special Equipment on the
vehicle when it was shipped from the factory. ALWAYS
REFER TO THIS INFORMATION W HEN O RD ERING
PARTS.
VEHICLE IDENTIFICATION
NUMBER
The VIN is the legal identifier of the vehicle. On all
models except Forward Control, it is located on a plate
which is attached to the left top of the instrument panel
and can be seen through the windshield from the outside
of the vehicle (figure 2). On Forward Control models, the
plate is on the dash and toe panel. To find out the
F-00687
Figure 2—VIN Location
manufacturer, model and chassis type, engine type, GVW
range, model year, plant code, and sequential number,
refer to figure 3.
CERTIFICATION LABEL
The Certification Label shows the GVWR, and the front
and rear GAWRs, and the Payload Rating for your vehicle
(figure 4).
Gross Vehicle Weight (GVW) is the weight of the
orginally equipped vehicle and all items added to it after-it
has left the factory. This would include bodies, winches,
booms, etc.; the driver and all occupants; and the load the
vehicle is carrying. The GVW must not exceed the
GVWR. Also, the front and rear gross axle weights must
not exceed the front and rear GAWRs.
The Payload Rating shown on the label is the maximum
allowable cargo load (including the weight of the driver
and all occupants) that the vehicle can carry based on all

OA-2 GENERAL INFORMATION
13 2 1 6 1
Nation of Origin
1 » U S Built
2 * Canadian Built
3 » Mexi an Built
Manufacturers
G * Genera) Motors
Code Make
AChevrolet Bus'
8 Chevrolet In omplete
C Chevrolet Tru k
D GMC In omplete
JGMC Bus'
K GMC MPV
N Chevrolet MPV
TGMC Tru k
'Van with 4th Seat
Cod* Body Type
0 Chassis Only
1Hi-Cube/Cutaway Van
2 Forward Control
3Four-Door Cab
4Two-Door Cab
5Van
6Suburban
7 Motor Home Chassis
8Utility < Blazer / Jimmy)
9Extended Cab
Code Year
K 1989
Assembly Plant
B Baltimore, MO
E Pontia East, Ml
F Flint. Ml
J Janesville. Wl
S St Louis, MO
V Pontia , Ml
Z Fort Wayne. IN
0 Pontia , Ml
1 Oshawa, ON
2 Moraine, OH
3 Detroit, Ml
4 S arborough, ON
5 London, ON
7 Lordstown, OH
8 Shreveport, LA
GVWR/BRAKE SYSTEM
Code GVWR flange Brake System
B3001-4000 Hydrauli
C 4001 5000 Hydrauli
D5001-6000 Hydrauli
E 6001 7000 Hydrauli
F 7001 8000 Hydrauli
G 8001-9000 Hydrauli
H 9001-10.000 Hydrauli
J 10,001-14,000 Hydrauli
K14.001-16.000 Hydrauli
Line and Chassis Type
Chassis
Code Line Type
CConventional Cab 4x2
nConventional Cab 4x2
0Military Tru k 4x4
KConventional Cab 4x4
VConventional Cab 4x4
GVan 4x2
pForward Control 4x2
SSm Conventional Cab 4x2
T Sm Conventional Cab 4x4
M Sm Van 4x2
Engine Type and Make
Code Producer Type RPO
CDDA 6 2L V8 Diesel LH6
ECPC-North 2 SLL4TBI LN8
H CPC 5 OL V8 TBI L03
JDDA 6.2L V8 Diesel LL4
K CPC 5 7L V8TBI L05
MCPC 5 7L V8 4 BBL LT9
N CPC 7 41 V8 TBI L19
PCummins 3 9L Diesel —
n CPC 2.8L V6 TBI LL2
T CPC 4.8L L6 1 BBL L25
w CPC 7.4L V8 4 BBL LE8
zCPC 4 3L V6TBI LB4
F6251
Figure 3— Vehicle Identification Number
factory installed equipment on the vehicle. The Payload
Rating is reduced if any accessories or other equipment
is added to the vehicle after final date of manufacture.
The weight of these items should be determined and
deducted from the Payload Rating.
The ve hicle may also h ave a G C W R (G ro ss
C o m bin atio n W eigh t R atin g ). T he G C W (G ro ss
Combination Weight) is the total weight of the loaded tow
vehicle (including passengers) and a loaded trailer.
The tires on the vehicle must be the proper size and
properly inflated for the load which you are carrying. The
MFD. BY GENERAL MOTORS CORPORATION
0 1 2/86 I
THIS VEHICLE EQUirPEO FOR
SEE OWNER’S MANUAL FOR ADDITIONAL INFORMATION
F-00597
Figure 4— Certification Label
vehicle Certification Label shows the originally equipped
tire size and recommended inflation pressures.
ENGINE IDENTIFICATION
NUMBER
Refer to figures 5, 6 and 7 to determine the location of
the engine I.D. number.
MODEL REFERENCE
Refer to figures 8 through 12 for determining vehicle
model. C, R, and S models are two wheel drive. K, V, and
T models are four wheel drive.
METRIC FASTENERS
Models are primarily dimensioned in the metric system.
M any fasteners are metric and are very close in
dimension to well-known customary fasteners in the inch
system. It is most important that replacement fasteners be
of the correct nominal diameter, thread pitch and strength.
Original equipment metric fasteners (except “beauty”
bolts, such as exposed bumper bolts, and cross recess
head screws) are identified by a num ber marking
indicating the strength of the material in the fastener as
outlined later. Metric cross recess screws are identified by
a Posidriv or Type 1A shown in figure 13. Either a Phillips
head or Type 1A cross recess screwdriver can be used in
Posidriv recess screw heads, but Type 1A cross recess
screwdrivers will perform better.

GENERAL INFORMATION OA-3
L6 ENGINE 4. Engine I.D. (Optional Location)
5. Engine Case Pad
6. Engine I.D.
1. Engine I.D. —
2. D istributor Pad
3. Engine I.D (Optional Location) V8 ENGINES-GAS
9. Engine I.D
V6 ENGINE V8 ENGINES-DIESEL F-00527
Figure 5—4.3L V6 and all V8 Engine I.D. Locations
NOTICE: Most metric fasteners have a blue
color coating. Ho ever, this should not be used
as positive identification as some fasteners are
not color coated.
General Motors Engineering Standards, along with
other North American Industries, have adopted a portion
of the standard metric fastener sizes defined by ISO
(International Standards Organization). This was done to
reduce the number of fastener sizes used and yet retain
the best strength qualities in each thread size. For
example, the customary 1/4-20 and 1/4-28 screws are
replaced by the metric M 6.0x1 screw which has nearly
the same diameter and has 25.4 threads per inch. The
thread pitch is in between the customary coarse and fine
thread pitches.
Metric and customary thread notation differ slightly. The
difference is shown in figure 14.
FASTENER STRENGTH
IDENTIFICATION
Most commonly used metric fastener strength properly
classes are 9.8 and 10.9 with the class identification
embossed on the head of each bolt. Customary (inch)
strength classes range from grade 2 to 8 with radial line
identification embossed on each bolt head. Markings
correspond to two lines less than the actual grade (i.e.
grade 7 bolt will exhibit 5 embossed radial lines on the
bolt head). Some metric nuts will be marked with single
digit strength identification numbers on the nut face.
Figure 6 shows the different strength markings.
When replacing metric fasteners, be careful to use bolts
and nuts of the same strength or greater than the original
fasteners (the same number marking or higher). It is
likewise important to select replacement fasteners of the
correct size. Correct replacement bolts metric fasteners
available in the aftermarket parts channels were designed
to metric standards of countries other than the United
States, and may be of a lower strength, may not have the
numbered head marking system, and may be of a
different thread pitch. The metric fasteners used on GM
_ ___ .. ; .....~

OA-4 GENERAL INFORMATION
products are designed to new, international standards that
may not yet be manufactured by some non-domestic bolt
and nut suppliers. In g eneral, except for special
applications, the common sizes and pitches are
M6.0 x 1 M 10 x 1.5
M8 x 1.25 M 1 2 x1.75
SIX LOBED SOCKET
HEAD FASTENERS
Six lobed socket head (Torx) fasteners are used in some
applications on vehicles covered in this manual (figure
15). The door striker bolt is of this design.
PREVAILING TORQUE FASTENERS
A prevailing torque nut is designed to develop an
interference between the nut and bolt threads. This is
most often accomplished by distortion of the top of an
all-metal nut by using a nylon patch on the threads in the
middle of the hex flat. A nylon insert may also be used as
a method of interference between nut and bolt threads
(figure 16).
A prevailing torque bolt is designed to develop an
interference between bolt and nut threads, or the threads
of a tapped hole. This is accomplished by distorting some
of the threads or by using a nylon patch or adhesive
(figure 16).
RECOMMENDATIONS FOR REUSE
1. Clean, unrusted prevailing torque nuts and bolts
may be reused as follows
a. Clean dirt and other foreign material off the
nut or bolt.
b. Inspect the nut or bolt to insure there are no
cracks, elongation, or other signs of abuse of
overtightening. (If there is any doubt, replace
with a new prevailing torque fastener or equal
or greater strength.)
c. Assemble the parts and hand start the nut or
bolt.
d. O bserve that, b efore fasten er seats, it
develops torque per the chart in figure 13 (if
there is any doubt, replace with a new
prevailing torque fastener of equal or greater
strength).
e. Tighten the fastener to the torque specified in
the appropriate section of this manual.
2. Bolts and nuts which are rusty or damaged should
be replaced with new parts or equal or greater
strength.
Tools designed for these fasteners are available
commercially. However, in some cases, if the correct tool
is not available, a hex socket head wrench may be used.

GENERAL INFORMATION OA-5
Figure 8—RV Models

OA-6 GENERAL INFORMATION
Figure 9—G and P Models
G VAN MODELS
CUTAWAY VAN
P MODELS
VALUE VAN (STEP VAN)
(ALUMINUM) MOTOR HOME CHASSIS
RALLY (SPORTVAN)
MAGNAVAN (HI-CUBE VAN)
VALUE VAN (STEP VAN)
(STEEL) FORWARD CONTROL CHASSIS
B-09178
VANDURA (CHEVY VAN)

GENERAL INFORMATION OA-7
Figure 11—ST Models

OA-8 GENERAL INFORMATION
Passenger Van
Cargo Van
B-09261
Figure 12—M Models
1. Grade 2 (GM 200-M)
2. Grade 5 (GM 280-M)
3. Grade 7 (GM 290-M)
4. Grade 8 (GM 300-M)
5. M anufacturer’s Identification
6. Nut Strength Identification
7. Identification Marks (Posidriv Scre Head)
F-00695
1. Customary Bolt— 1/4-20
2. Metric B olt— M6.0x1
A. 1/4-inch
B. 6 mm
C. 20 Threads Per Inch
D. 1 Thread Per M illim eter
(25.4 Threads Per Inch) F-00705
Figure 14—Thread Notation
T - Internal Drive
E - External Drive
B-02221
Figure 13— Bolt and Nut Identification Figure 15—Six Lobed Socket Head Fasteners

GENERAL INFORMATION OA-9
A. M etric Sizes 1. Top Lock Type 6. Nylon Strip Or Patch
B. Inch Sizes 2. Center Lock 7. Nylon W asher Insert
3. Dry Adhesive Coating 8. Nylon Patch
4. Out Of Round Thread 9. Nylon Insert
5. Deformed Thread Profile B-02406
Figure 16—Torque Nuts and Bolt Chart

Figure 17—Conversion Table
CONVERSION TABLE
Multiply by to get equivalent
number of Multiply to get equivalent
by number of
LENGTH ACCELERATION
Inch 25.4 millimeters (mm) Foot/sec2 0.304 8 meter/sec2 (m/s2)
Foot 0.304 8 meters (m) Inch/sec2 0.025 4 meter/sec2
Yard 0.9144 meters TORQUE
Mile 1.609 kilometers (km) Pound-inch 0.112 98 ne ton-meters (Nm)
AREA Pound-foot 1.355 8 ne ton-meters
Inch2 645.2 millimeters2 (mm2) POWER
Foot2
Yard2
6.45
0.092 9
0.836 1
VOLUME
centimeters2 (cm2)
meters2 (m2)
meters2
Horsepo er 0.746 kilo atts (kW)
PRESSURE OR STRESS
Inches of ater
Pounds/sq. in. 0.249 1 kilopascals (kPa)
6.895 kilopascals
ENERGY OR WORK
Inch3 16.387
16.387
0.0164
liters
3.785 4
0.764 6
MASS
mm3
Quart 0.946 4
Gallon
Yard3
cm3
liters (I)
liters
meters3 (m3)
BTU
Foot-pound
Kilo att-hour
1 055 joules (J)
1.355 8 joules
3 600 000 joules (J $ one W)
or 3.6 x 106
LIGHT
1.076 4 lumens/meter2 (lm/m2)
FUEL PERFORMANCE
Pound
Ton 0.453 6 907.18 kilograms (kg)
kilograms (kg)
tonne (t)
Foot candle
Ton 0.907 Miles/gal 0.425 1 kilometers/liter (km/l)
FORCE Gal/mile 2.352 7 liter/kilometer (l/km)
Kilogram
Ounce 9.807 ne tons (N)
ne tons
VELOCITY
0.278 0 Miles/hour 1.609 3 kilometers/hr. (km/h)
Pound 4.448 ne tons
TEMPERATURE
Degree
Fahrenheit (t°F-32) -r 1.8 degree Celsius (C)
o
cn
CD
-vl
0A-10 GENERAL INFORMATION

GENERAL INFORMATION OA-11
DECIMAL AND METRIC EQUIVALENTS
Fractions Decimal In. Metric mm Fractions Decimal In. Metric mm
1/64 0.015625 0.39688 33/64 0.515625 13.09687
1/32 0.03125 0.79375 17/32 0.53125 13.49375
3/64 0.046875 1.19062 35/64 0.546875 13.89062
1/16 0.0625 1.58750 9/16 0.5625 14.28750
5/64 0.078125 1.98437 37/64 0.578125 14.68437
3/32 0.09375 2.38125 19/32 0.59375 15.08125
7/64 0.109375 2.77812 39/64 0.609375 15.47812
1/8 0.125 3.1750 5/8 0.625 15.87500
9/64 0.140625 3.57187 41/64 0.640625 16.27187
5/32 0.15625 3.96875 21/32 0.65625 16.66875
11/64 0.171875 4.36562 43/64 0.671875 17.06562
3/16 0.1875 4.76250 11/16 0.6875 17.46250
13/64 0.203125 5.15937 45/64 0.703125 17.85937
7/32 0.21875 5.55625 23/32 0.71875 18.25625
15/64 0.234375 5.95312 47/64 0.734375 18.65312
1/4 0.250 6.3500 3/4 0.750 19.05000
17/64 0.265625 6.74687 49/64 0.765625 19.44687
9/32 0.28125 7.14375 25/32 0.78125 19.84375
19/64 0.296875 7.54062 51/64 0.796875 20.24062
5/16 0.3125 7.93750 13/16 0.8125 20.63750
21/64 0.328125 8.33437 53/64 0.828125 21.03437
11/32 0.34375 8.73125 27/32 0.84375 21.43125
23/64 0.359375 9.12812 55/64 0.859375 21.82812
3/8 0.375 \ 9.52500 7/8 0.875 22.22500
25/64 0.390625 9.92187 57/64 0.890625 22.62187
13/32 0.40625 10.31875 29/32 0.90625 23.01875
27/64 0.421875 10.71562 59/64 0.921875 23.41562
7/16 0.4375 11.11250 15/16 0.9375 23.81250
29/64 0.453125 11.50937 61/64 0.953125 24.20937
15/32 0.46875 11.90625 31/32 0.96875 24.60625
31/64 0.484375 12.30312 63/64 0.984375 25.00312
1/2 0.500 12.7000 1 1.00 25.40000
B-07676
Figure 18—Decimal and Metric Equivalents

A-6 AIR CONDITIONING COMPRESSOR 1B1-1
...
SECTION 1
AIR CONDITIONING
CONTENTS
SUBJECT * PAGE
A-6 Air Conditioning Compressor..............................................................................................................................................1B1-1
V-5 Air Conditioning Compressor..............................................................................................................................................1B2-1
R-4 Air Conditioning Compressor..............................................................................................................................................1B3-1
HR-6 Air Conditioning Compressor............................................................................................................................................1B4-1
SD-709 Air Conditioning Compressor.......................................................................................................................................1B5-1
^ SECTION 1B1
A-6 AIR CONDITIONING COMPRESSOR
CONTENTS
SUBJECT PAGE
Description............................................................................................. .....................................................................................1B1- 1
Minor Repair to the Compressor......................................................................................................... .. ..................... .1B1- 3
Clutch Plate and Hub Assembly Replacement......................................................................... ........... .. .'. „ . . . .. .1B1- 3
Pulley and Bearing Assembly Replacement........................................................................... .. ..................................1B1- 4
Clutch Coil and Housing Assembly Replacement................................................... . , ........................... ............. .1B1- 6
Major Repair to the Compressor...................................................................................................... ............................. .. .. .1B1 - 7
Shaft Seal Replacement............................................................................................................. *................ ...................... 1B1- 7
Pressure Relief Valve Replacement.................................................................................................... ............................. 1B1 - 9
Compressor Disassembly...................................................................................................... ..................................................1B1-10
Gaging Operation....................................................................................................................................................................1B1-12
Gaging Procedure..................................................................................................................................................................1B1-14
Piston Ring Replacement....................................................................................................................................................1B1-16
Compressor Assembly............................................................................................................................................................. 1B1-18
Leak Testing............................................................................................................................................................................... 1B1-22
Specifications.............................................................................................................................................................................1B1-23
Special Tools............................................................................................................................................................................... 1B1-24
DESCRIPTION
When servicing the Harrison A-6 compressor, prevent
dirt or foreign material from getting on or into the com
pressor parts and system during disassembly or reassem
bly.
Keep tools and work area clean. Clean the compressor
exterior before disassembly. Clean parts with trichloroe-
thane, naptha or Stoddard solvent, kerosene or equiva
lent. Dry with air.
Use a non-lint producing type cloth to clean each part.
Although certain service operations can be performed
without removing the compressor from the vehicle, the op
erations 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 1).
For compressor removal and installation, refer to the
proper truck service manual.
Do not kink or place excessive tension on lines or
hoses.
After removing the compressor from the vehicle, drain
and measure the refrigerant oil. Add new 525 viscosity
refrigerant oil after repair. Refer to “Specifications.”
IDENTIFICATION
An identification label attached to the compressor
provides the name of the manufacturer, model number
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.

1. Nut
2. C lutch
3. Ring
4. Pulley Bearing Ring
5. Bearing
6. Pulley
7. Clutch Coil Ring
8. Coil
9. Shell
10. Sleeve Seal
11. Flat Seal
12. Ring
13. Seat Seal
14. Shaft Seal
15. Shaft Seal (O-ring)
16. Front Head
17. Seal (Front)
18. Discharge Valve
Plate (Front)
19. Reed Suction
Valve (Front)
20. Pin
21. Bearing
22. Drain Scre
23. Gasket
24. Sleeve
25. Seal
26. Tube
27. Race
28. Bearing
29. Cylinder (Front)
30. Sleeve
31. Seal
32. Piston
33. Ring (Piston)
34. Ball
35. Seal (Ball)
36. Key
37. Ring (Piston)
38. Pin
39. Shaft
40. Race
41. Bearing
42. Cylinder (Rear)
43. Seal
44. Tube
45. Pin
46. Plate
47. Bearing
48. Discharge Valve
Plate (Rear)
49. Reed Suction Valve (Rear)
50. Inner Gear
51. O uter G ear
52. Seal (Rear)
53. Nut
54. R ear Head
55. Seal
56. Pressure Relief Valve
57. Seal
58. Screen
1B1-2 A-6 AIR CONDITIONING COMPRESSOR
F-01538
Figure 1—Compressor Component View