air condition GMC C-SERIES 1999 Owner's Manual

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6-65
Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch
-up
materials available from your dealer or other service
outlets. Larger areas of finish damage can be corrected
in your dealer's body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust control
can collect on the underbody. If these are not removed,
accelerated corrosion (rust) can occur on the underbody
parts such as fuel lines, frame, floor pan and exhaust
system even though they have corrosion protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody vehicle washing system
can do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage
can take two forms: blotchy, ringlet
-shaped
discolorations, and small irregular dark spots etched into
the paint surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of new
vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.
This applies only to materials manufactured and sold by
General Motors. Bodies, body conversions or equipment
not made or sold by General Motors are not covered.
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6-71
Name Circuits Protected
CHAS Exhaust Brake, Air Suspension
Dump Valve, Air Dryer, HYD
ABS ECHU
PARK LP Auxiliary Wiring, Air Conditioner
Controls, Parking Lamps, Turn
Signals, Taillamps, Stoplamps,
Marker Lamps, Trailer Running
Lamps, Lighted Mirrors, Radio
Receiver, Mirror Clearance Lamps
HORN Horn/Diagnostic Connector
PRK BRK Parking Brake Module
FUEL Heated Fuel Filter (Diesel
Engines) or Fuel Pump
(Gasoline Engines)
AXLE Heated Mirrors, Radiator Shutters,
Tw o
-Speed Axle Motor,
Tw o
-Speed Axle Switch
MRKR LP Roof Marker Lamps,
Trailer Marker Lamps,
Marker Lamp RelayName Circuits Protected
CIG/AUX Cigarette Lighter,
Auxiliary Power Jacks
AUX Auxiliary Wiring Relay
IGN RLY/VIN Vehicle Interface Module
(Diesel Engines) or Generator,
Coil, Injectors (Gasoline Engines)
WDO Power Windows
CRNK Starter Relay
IGN SW Instrument Panel Cluster Telltales
AUX Auxiliary Wiring
RDO Radio, Auxiliary Wiring
DR LK Power Door Locks
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6-73
Name Circuits/Circuit Breakers
Protected
STP/HAZ
TURNStop Lamp, Turn Signal/Hazard
Lights, Fuel, Ignition Relay
(Gasoline Engines)
IGN SW3 Air Conditioner, Ignition Switch,
Axle, ChassisName Circuits/Circuit Breakers
Protected
INT/EXT
LIGHTSParking Lamps,
Dome/Panel Lights
HEAD LAMP Headlamps,
Daytime Running Lamps
AUX WRG Auxiliary, Park Brake
IGN SW1 Ignition Switch, Wash/Wipe,
Crank, Radio
HYD PUMP Hydraulic Brake,
Brake Pump Motor
HYD ABS EHCU
PWR
WDO/LCKSWindow, Door Locks
PARK BRK Parking Brake Motor
BLOWER
HORNBlower, Horn, Cigarette
Lighter/Auxiliary
FUEL/ENGINE Empty
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6-77
Air Conditioning Refrigerants
Not all air conditioning refrigerants are the same.
If the air conditioning system in your vehicle needs
refrigerant, be sure the proper refrigerant is used.
If you're not sure, ask your dealer.
Air Conditioning Refrigerant Capacity
Refrigerant R-134a 2.5 lbs. (1.134 kg). . . . . . . . . . . .
This capacity (volume) is approximate.
Normal Maintenance Replacement
Parts
Allison Transmission External Filters
Engine GM (AC) Part Number
7.2L 25011122 (PF897). . . . . . . . . . . . . . . . . . . . . . .
7.4L 25011122 (PF897). . . . . . . . . . . . . . . . . . . . . . .
Air Compressor Filter
Air Compressor GM Part Number
Bendix Tu
-Flo
550 (13.2 CFM)2467368
Service Replacement Part and
Filter Recommendations
Engine 7.2L 7.4L
RPO LG5 LP4/L21
Spark Plug Ð AC Type R41
-932
ÐGap Ð 0.060 inch
(1.52 mm)
ÐTorque Ð 22.0 lb. ft.
(30.0 Nm)
Oil Filter CAT

2P4004 AC Type PF-932
PCV Valve Ð AC Type CV
-774C
Air Cleaner* Donaldson
P522606Donaldson
P533355
Fuel Filter AC
-TP-915 Pri-
mary**AC Type GF-481
Pressure Caps RC
-54 Ð
*Optional Davco (K28) D350921 spin
-on type filter
located in component box.
**Optional Cold Weather (KUK) Racor B6484GM
spin
-on type located in component box. Optional Davco
heated fuel water separator mounted on the side of the
diesel engine.
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7-2
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet, or your
GM dealer for details.
Introduction
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance procedures
are important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper fluid
levels or the wrong tire inflation can increase the level
of emissions from your vehicle. To help protect our
environment, and to keep your vehicle in good
condition, please maintain your vehicle properly.
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7-3 How This Section is Organized
This maintenance schedule is divided into five parts:
ªPart A: Scheduled Maintenance Servicesº shows
what to have done and how often. Some of these
services can be complex, so unless you are technically
qualified and have the necessary equipment, you should
let your dealer's service department or another qualified
service center do these jobs.
CAUTION:
Performing maintenance work on a vehicle can
be dangerous. In trying to do some jobs, you can
be seriously injured. Do your own maintenance
work only if you have the required know
-how
and the proper tools and equipment for the job.
If you have any doubt, have a qualified
technician do the work.
If you are skilled enough to do some work on your
vehicle, you will probably want to get the service
information. See ªService and Owner Publicationsº in
the Index.ªPart B: Owner Checks and Servicesº tells you
what should be checked and when. It also explains what
you can easily do to help keep your vehicle in
good condition.
ªPart C: Recommended Fluids and Lubricantsº
lists some recommended products to help keep your
vehicle properly maintained. These products, or their
equivalents, should be used whether you do the work
yourself or have it done.
ªPart D: Maintenance Recordº provides a place
for you to record the maintenance performed on your
vehicle. Whenever any maintenance is performed, be
sure to write it down in this part. This will help you
determine when your next maintenance should be done.
In addition, it is a good idea to keep your maintenance
receipts. They may be needed to qualify your vehicle for
warranty repairs.
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7-4
Part A: Scheduled Maintenance
Services
Using Your Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we don't know
exactly how you'll drive it. You may drive very short
distances only a few times a week. Or you may drive
long distances all the time in very hot, dusty weather.
You may use your vehicle in making deliveries or in
many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good
condition, see your GM dealer.
This part tells you the maintenance services you should
have done and when you should schedule them. If you
go to your dealer for your service needs, you'll know
that GM
-trained and supported service people will
perform the work using genuine GM parts.The proper fluids and lubricants to use are listed in Part C.
Make sure whoever services your vehicle uses these. All
parts should be replaced and all necessary repairs done
before you or anyone else drives the vehicle.
This schedule is for vehicles that:

carry passengers and cargo within recommended
limits. You will find these limits on your vehicle's
Certification/Tire label. See ªLoading Your Vehicleº
in the Index.

are driven on reasonable road surfaces within legal
driving limits.

use the recommended fuel. See ªFuelº in the Index.
Scheduled Maintenance Supplements
If your vehicle has a Caterpillar diesel engine, your
GM Owner's Manual is supplemented by the Caterpillar
Diesel Engine Operation & Maintenance Manual. If your
vehicle has an Allison transmission, your GM Owner's
Manual is supplemented by an Allison Transmission
Operator's Manual. Always refer to these manuals for
related maintenance services.
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7-7

Replace air conditioning filter dryer (or every
18 months, whichever occurs first, and whenever
refrigerant charge is lost for any reason).

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic brake caliper service (or every 6 months,
whichever occurs first). (22)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Clutch pedal free travel service. (10)

Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first);
lubricate linkage.
21,000 Miles (35 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
24,000 Miles (40 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Lubricate door hinge pins and rollers with engine oil.

Wheel bearing (grease type) service (or every
24 months, whichever occurs first, and whenever
hubs are removed). (23)

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Clutch pedal free travel service. (10)

Throttle linkage service. (19)

Thermostatically controlled engine cooling
fan service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

Air intake system service (or every 24 months,
whichever occurs first). (4)(5)(24)

Thermostatically controlled air cleaner service
(or every 24 months, whichever occurs first).
(3)(4)(25)

(Continued)
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7-9 36,000 Miles (60 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Inspect door hinge pins and bushings and replace as
necessary. Lubricate door hinge pins and rollers with
engine oil.

Replace air conditioning filter dryer (or every
18 months, whichever occurs first, and whenever
refrigerant charge is lost for any reason).

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic brake caliper service (or every 6 months,
whichever occurs first). (22)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Clutch pedal free travel service. (10)

Throttle linkage service. (19)

Thermostatically controlled engine cooling
fan service. (4)(20)
Shields and underhood insulation service. (4)(5)(21)

Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours,
whichever occurs first).

Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first);
lubricate linkage.
39,000 Miles (65 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
42,000 Miles (70 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Lubricate door hinge pins and rollers with engine oil.

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Clutch pedal free travel service. (10)
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7-11 51,000 Miles (85 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
54,000 Miles (90 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Inspect door hinge pins and bushings and replace if
necessary. Lubricate door hinge pins and rollers with
engine oil.

Replace air conditioning filter dryer (or every
18 months, whichever occurs first, and whenever
refrigerant charge is lost for any reason).

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)

Hydraulic brake caliper service (or every 6 months,
whichever occurs first). (22)

Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)

Clutch pedal free travel service. (10)
Spark plug service. (3)(28)

Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first);
lubricate linkage.
57,000 Miles (95 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
60,000 Miles (100 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Replace fuel filter(s) (or every 12 months, whichever
occurs first). (3)

Air cleaner filter replacement service (or every
24 months, whichever occurs first). (3)(4)(27)

Steering system service. (13)

Front and rear suspension service. (14)

Spring
-to-axle U-bolts and shackle bolts service. (16)
(Continued)
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