maintenance schedule GMC C-SERIES 1999 User Guide

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6-44
Other Service Items
Component Box
Your vehicle has a component box along the left frame rail.
What is in the box depends on what options are on your
vehicle. Normally, the fuel filter, air dryer, Luberfiner oil
filter, emission canister or other components are in there.
To get into the box, you first have to remove the top
cover. To do that, remove the two 8 mm bolts on top and
the single 8 mm bolt at the top front. Then, pull the
cover toward you and lift it off.You can then remove the front cover if you need to, by
removing the two 8 mm bolts and pulling it off.
When you're through, be sure to put the front cover on,
before you put on the top cover.
Fuel Filter (Gasoline Engines)
The steel fuel filter is located inside the component box
at the rear. See your Maintenance Schedule for
recommended service intervals.
If your vehicle is equipped with the optional Davco
spin
-on type filter, it is also located in the component box.
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6-45 Fuel Filter (Diesel Engines)
The ACDelco
fuel filter is located in the component
box. See your Maintenance Schedule for recommended
service intervals.
Primary Fuel Filter and Water Separator
(Option)
If you have a Caterpillar

diesel engine, you may
have this spin
-on filter.
It is in the component box
on the driver's side behind
the fender.
It has a clear plastic drain bowl at the bottom. Check the
drain bowl occasionally for any water or particles. To
drain the bowl, shut off the engine. Then partially open
the drain valve at the bottom of the filter. See ªEngine
Oilº in the Index for proper disposal procedures.
Secondary Fuel Filter and Water
Separator/Heater (Option)
If you have a Caterpillar

diesel engine, you may have
this spin
-on filter and fuel
separator/heater. It is
mounted on the passenger's
side of the engine.
It has a metal drain bowl at the bottom. Occasionally, check
the bowl for any water or particles. To check or drain the
bowl, shut off the engine. Then push up on the spring loaded
drain valve until clear fuel is flowing from the valve. The
particles or water will drain out first. See ªEngine Oilº in the
Index for proper disposal procedures.
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6-47 Front Wheel Bearings with Oil-Filled Hubs
If your vehicle has oil-filled
hubs, occasionally check to
see if they have enough oil.
You can tell by looking into
the sight glass to see if there
is oil there.
If there isn't, clean the rubber fill plug in the center of
the glass, and then remove it. Be careful not to allow
any dirt or water to get into the oil. Add enough of the
recommended oil to bring it up to the level mark that
you'll see on the glass.
Refer to your Maintenance Schedule for the proper oil
to use.
When you fill the hub, check the glass again after
driving a short distance. It takes a while for the oil to
flow through the system, and you may find that you
have to add a little more to fill it to the proper level.
Air Conditioning System
Every now and then, have your dealership check your
air conditioning system to be sure it has not lost any
cooling ability. If you think the system is not working
properly, have your GM Truck dealer check it out as
soon as possible.
The air conditioning won't work when the temperature
outside is below 40
F (4
C).
NOTICE:
If your vehicle is equipped with factory air
conditioning, the system is charged with the
R
-134a refrigerant. Servicing of the air
conditioning system should be performed by a
trained service technician.
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7-
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7-1
Section 7 Scheduled Maintenance Services
This section covers the maintenance required for your vehicle. Your vehicle needs these services to retain its safety,
dependability and emission control performance.
7
-2 Introduction
7
-4 Part A: Scheduled Maintenance Services
7
-5 Scheduled Maintenance7
-23 Part B: Owner Checks and Services
7
-28 Part C: Recommended Fluids and Lubricants
7
-31 Part D: Maintenance Record
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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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7-5
Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be performed after 100,000 miles
(166 000 km) at the same intervals. The services shown
after 100,000 miles (166 000 km) should be performed
at those same intervals.
This vehicle has a computer that lets you know when to
change your engine oil. This is not based on mileage,
but on engine revolutions and engine operating
temperature. When the computer has calculated that the
oil needs changing, the Oil Life Indicator will indicate
that a change is necessary.
See ªFootnotesº at the end of this Maintenance Schedule
for further explanation of maintenance services and
Caterpillar

diesel application.
100 Miles (160 km)
Wheel stud nut service. (45)
500 Miles (800 km)
Wheel stud nut service. (45)
1,000 Miles (1 600 km)
Wheel stud nut service. (45)(46)
3,000 Miles (5 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
Clutch pedal free travel service. (10)
Rear axle air shift motor service. (11)
6,000 Miles (10 000 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)
9,000 Miles (15 000 km)
Engine oil and filter service. (3)(9)
Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
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7-22

Test air lines for leaks; tighten as needed. Replace
compressor filter.

Inspect air parking brake chamber for leaks and
damage. Inspect lines and hoses for leaks, cracks,
chafing, etc. Also check all attachments for
tightness, wear or damage. Note: The spring brake
section of the rear brake diaphragms are
non
-serviceable.

Replace the air compressor filter element, mounted
on the air compressor. For remote air compressor
intake service, refer to air cleaner filter replacement.
(40) = Clean and lubricate air brake automatic slack
adjuster. Check pushrod travel and auto adjustment
operation. Have serviced if needed.
(41) = Air brake chamber service: Check operation,
mounting, clamps and air lines and check for leaks.
(42) = Trailer brake hand control valve service: Check
operation; lubricate cam and follower.
(44) = Air brake service: Remove, disassemble, clean
and inspect the safety valve, standard brake chamber,
quick release valve, quick release/double check valve
combination, parking brake control valve, double check
valve, pressure protection valve and alcohol injector. Remove, disassemble and clean the application valve;
replace parts showing wear. Remove, disassemble, clean
and inspect the spring brake control valve; replace
rubber parts.
(45) = For Stud Piloted Wheels Only: Tighten the wheel
stud nuts to the specified torque values at 100 miles
(160 km), 500 miles (800 km) and 1,000 miles
(1 600 km) and then every 1,000 miles (1 600 km)
thereafter. See ªTightening the Wheel Nutsº in
the Index.
(46) = For Hub Piloted Wheels Only: Tighten the wheel
stud nuts to the specified torque values at 1,000 miles
(1 600 km). Thereafter, tighten them 1,000 miles
(1 600 km) after each time the wheel is removed. See
ªTightening the Wheel Nutsº in the Index.
(47) = Short Trip/City Maintenance Schedule. See
ªMaintenance Schedule Definitionº in the introduction
pages at the beginning of this section.
(48) = Long Trip/Highway Maintenance Schedule. See
ªMaintenance Schedule Definitionº in the introduction
pages at the beginning of this section.
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7-31
Part D: Maintenance Record
After the scheduled services are performed, enter the
date, odometer reading and services performed on the
maintenance record charts provided here. Any additional
information from ªOwner Checks and Servicesº can beadded on the following record pages. Also, you should
retain all maintenance receipts. Your owner information
portfolio is a convenient place to store them.
Maintenance Record
DATEODOMETER
READINGSERVICED BYMAINTENANCE PERFORMED
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8-8
CURRENT PUBLICATIONS FOR 1999 GMC
SERVICE MANUALS
Service Manuals have the diagnosis and repair information
on engines, transmission, axle, suspension, brakes,
electrical, steering, body, etc.
RETAIL SELL PRICE: $90.00
TRANSMISSION, TRANSAXLE, TRANSFER CASE
UNIT REPAIR MANUAL
This manual provides information on unit repair service
procedures, adjustments and specifications for the
1999 GM transmissions, transaxles and transfer cases.
RETAIL SELL PRICE: $50.00
SERVICE BULLETINS
Service Bulletins give technical service information needed
to knowledgeably service General Motors cars and trucks.
Each bulletin contains instructions to assist in the
diagnosis and service of your vehicle.OWNER'S INFORMATION
Owner publications are written directly for Owners and
intended to provide basic operational information about the
vehicle. The owner's manual will include the Maintenance
Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner's Manual and
Warranty Booklet.
RETAIL SELL PRICE: $15.00
Without Portfolio: Owner's Manual only.
RETAIL SELL PRICE: $10.00
CURRENT & PAST MODEL ORDER FORMS
Service Publications are available for current and past
model GM vehicles. To request an order form, please
specify year and model name of the vehicle.
PLEASE COMPLETE THE ORDER FORM SHOWN ON
THE FOLLOWING PAGE AND MAIL TO:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207OR ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM ± 6:00 PM Eastern Time
For Credit Card Orders Only (VISA±MasterCard±Discover)
1999 GMC SERVICE PUBLICATIONS ORDERING INFORMATION
The following publications covering the operation and servicing of your vehicle can be purchased by filling out
the Service Publication Order Form in this book and mailing it in with your check, money order,
or credit card information to Helm, Incorporated (address below.)
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