1999 GMC C-SERIES change time

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6-18
CAUTION:
Gasoline Engines Only: Operating the engine
with the air cleaner/filter off can cause you or
others to be burned. The air cleaner not only
cleans the air, it stops flame if the engine
backfires. If it isn't there, and the engine
backfires, you could be burned. Don't drive with
it off, and be careful working on the engine with
the air cleaner/filter off.
NOTICE:
Gasoline Engines Only: If the air cleaner/filter is
off, a backfire can cause a damaging engine fire.
And, dirt can easily get into your engine, which
will damage it. Always have the air cleaner/filter
in place when you're driving.
Your vehicle may also be equipped with an optional
Filterminder gage. See ªWarning Lights, Gages and
Indicatorsº in the Index.
Automatic Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Allison Automatic Transmission
Operator's Manual to find out when to change your
transmission fluid and filters.
How to Check and What to Use
The Allison Automatic Transmission Operator's Manual
that came with the vehicle shows how to check the
automatic transmission fluid and what fluid to use.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire. Be
sure to get an accurate reading if you check your
transmission fluid.
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6-19 Automatic Transmission External Filter
Your automatic transmission spin-on type filter requires
periodic replacement. It is mounted just behind the
radiator on the outside of the passenger's side frame rail.
Consult the Allison Automatic Transmission Operator's
Manual that came with the vehicle for proper
change intervals.
Automatic Transmission External Filter
With Service Trans Filter Indicator Light
(Option)
This automatic transmission spin-on type filter is
mounted to the left of the transmission. It requires
replacement when the SERVICE TRANS FILTER
indicator light on the instrument panel comes on or
every three years, whichever occurs first.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Maintenance Schedule to find out
when to change your transmission fluid and filters.
How to Check and What to Use
The Eaton Fuller Transmission Operator's Manual that
came with the vehicle shows how to check the manual
tranmsmission fluid and what fluid to use.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire. Be
sure to get an accurate reading if you check your
transmission fluid.
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6-20
Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it.
See ªScheduled Maintenance Servicesº in the
Maintenance Schedule.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Maintenance Schedule.
Rear Axle Shift Motor (Option)
When to Check and Change Fluid
If you have an optional air-shift two-speed, controlled
traction, or locking differential type rear axle, a good
time to check the fluid level in the axle shift motor is
when the rear axle lubricant is checked. Use refrigerant
oil (shift motor only).
How to Check Fluid
Remove the plug on the front plate of the axle shift
motor, add enough fluid to raise the level to the bottom
of the filler plug hole, then replace the plug.
What to Use
Refer to your Maintenance Schedule to determine what
kind of lubricant to use.
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6-57
CAUTION:
Rust or dirt on a wheel, or on the parts to which
it is fastened, can make the wheel nuts become
loose after a time. The wheel could come off and
cause an accident. When you change a wheel,
remove any rust or dirt from the places where the
wheel attaches to the vehicle. In an emergency,
you can use a cloth or paper towel to do this; but
be sure to use a scraper or wire brush later, if you
need to, to get all the rust or dirt off.
How Often to Check
Wheel tightness is so important you should have a
technician check nut tightness on all wheels with a
torque wrench every 1,000 miles (1 600 km).
When your vehicle is new or when a wheel or fastener is
new you should have a technician tighten the wheel
stud and rim clamp nuts, with a torque wrench, at
100, 500 and 1,000 miles (160, 800 and 1 600 km).
The reason for this is that the clamping system has to
seat before the fasteners will stay tightened.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted.
If wheel nuts keep coming loose, replace the wheel.
If the wheel leaks air, replace it.
Your dealer will know the kind of wheel you need.
CAUTION:
A leaking wheel could fail without warning. A
wheel designed for tubeless tires could be leaking
because it is damaged. Don't use an inner tube or
some other thing to try to stop the leaking. Get a
new wheel of the proper type.
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6-74
Replacement Bulbs
It is recommended that you use an AC
type bulb
whenever you need to replace one.
Before you replace any bulbs, be sure that all lamps are
off and the engine isn't running.
Capacities and Specifications
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing. They are subject to later change. If a part listed
here isn't the same as the part in your vehicle when it
was built, or if you have any questions, please contact
your GM Truck dealer.
Engine Identification and Data
Engine RPO LG5 LP4/L21
Engine Type 7.2L L6 7.4L V8
Fuel System HEUI SPFI
Firing Order
1
-5-3-6-2-41-8-4-3-6-5-7-2
Wheel Nut Torque
Refer to ªTightening the Wheel Nutsº in this section for
wheel nut torque information.
Cooling System Capacity
Model Quarts (Liters)
7.2L 32.0 (30.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 30.0 (28.4). . . . . . . . . .
7.4L 25.0 (23.7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 23.0 (22.7). . . . . . . . . .
Above capacities (volumes) are approximate.
Crankcase Capacity
Capacities (volumes) shown are for normal refill. Add
oil as indicated when the oil filter element is changed.
Capacities given are approximate
-- keep level within
the operating range. Do not operate with fluid level
below the ADD line.
Engine
Capacity
-- Quarts (Liters)
7.2L 21 (19.0)*
7.4L 8 (7.5)
*Additional oil is required with auxiliary oil filter
systems. Make sure to add enough extra oil to fill the
auxiliary oil filter system. For vehicles equipped with
the LUBERFINER 750
-C, add 14 quarts (13.25 L).
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8-9
PUBLICATION FORM
NUMBEROrders will be mailed within 10 days of receipt. Please allow adequate time for postal
service. If further information is needed, write to the address shown below or call
1-800-551-4123. Material cannot be returned for credit without packing slip with return
information within 30 days of delivery. On returns, a re-stocking fee may be applied
against the original order. ORDER TOLL FREE
(NOTE: For Credit Card Holders Only)1-800-551-4123(Monday-Friday 8:00 AM ± 6:00 PM EST)
FAX Orders Only 1-313-865-5927
Service Manual
NOTE: Dealers and Companies please provide dealer or company name, and also the
name of the person to whose attention the shipment should be sent.
Mail completed order form to:
HELM, INCORPORATED
P.O. Box 07130
Detroit, MI 48207
For purchases outside U.S.A. please write to the above address for quotation.
1999$90.00
1999
$50.00
1999
$15.00
1999
$10.00
TOTAL MATERIAL
Michigan Purchasers
U.S. Order Processing$5.00
Canadian Postage
GRAND TOTAL
add 6% sales tax
(See Note Below)
GM-GMC-ORD99 *(Prices are subject to change without notice and without incurring
obligation. Allow ample time for delivery.)Note to Canadian Customers: All listed prices are quoted in U.S. funds. Canadian residents
are to make checks payable in U.S. funds. To cover Canadian postage, add $11.50 plus the
U.S. order processing.
(CUSTOMER'S NAME) (ATTENTION)
(STREET ADDRESSÐNO P.O. BOX NUMBERS)
(CITY) (ZIP CODE)
DAYTIME TELEPHONE NO.(STATE)
AREA CODE
( )P
Check or Money
Order payable to
Helm, Inc. (USA funds
only Ð
do not send cash.)
VISA
Discover
Account
Number:
Expiration
Date mo/yr:
CUSTOMER SIGNATURE
S
ITEM DESCRIPTIONNAME YEAR VEHICLE MODEL
QTY.PRICE
EACH*TOTAL
PRICE1
9
9
9
G
M
H
I
P

T
OA
Y
M
E
N
T
Owner's Manual Without Portfolio Owner's Manual In Portfolio Car & Light Truck
Transmission Unit Repair
MasterCard
Check here if your billing address
is different from your shipping
address shown.
PUBLICATION FORM
NUMBER
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9-9
Storage, Vehicle 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stuck: In Sand, Mud, Ice or Snow 5-37 . . . . . . . . . . . . . . . . . .
Sun Visors 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank, Coolant 5-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank Pressure Cap 6-22 . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols, Vehicle v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tape Player Care 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Theft 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat 6-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tilt Steering Wheel 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tire Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing a Flat 5-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual Tire Operation 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation Check 7-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rims and Wheels 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Replacement 6-57 . . . . . . . . . . . . . . . . . . . . . . . . . . .
When It's Time for New 6-51 . . . . . . . . . . . . . . . . . . . . . . .
Top Strap 1-30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque, Wheel Nut 6-52 , 6-74 . . . . . . . . . . . . . . . . . . . . . . . .
Towing Your Vehicle 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trailer Brake Hand Control Valve 2
-39 . . . . . . . . . . . . . . . . . .
Trailer Connections 2-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission
Automatic 2
-20, 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission External Filter 6-19 . . . . . . . . . . .
Double-Clutching 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid, Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 6-75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 2-22, 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual, Fluid 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Gear Hold 2-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Clutch 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TTY Users 8-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn and Lane Change Indicator 2-33 . . . . . . . . . . . . . . . . . . .
Underbody Maintenance 6-65 . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle
Control 4-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damage Warnings iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification Number 6
-67 . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ventilation System 3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Visors, Sun 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltmeter 2-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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