Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of the
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Cooling System............................................5-24
Engine Coolant.............................................5-25Radiator Pressure Cap..................................5-31
Engine Overheating.......................................5-31
Engine Fan Noise.........................................5-33
Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
All-Wheel Drive..............................................5-45
Rear Axle
.......................................................5-46
Front Axle......................................................5-46
Noise Control System.....................................5-47
Tampering with Noise Control System
Prohibited.................................................5-47
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps..................................................5-49
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-51
Center High-Mounted Stoplamp (CHMSL).........5-52
Taillamps.....................................................5-52
Replacement Bulbs.......................................5-53
Windshield Wiper Blade Replacement..............5-54
Section 5 Service and Appearance Care
5-1
A. Battery. SeeBattery on page 5-39.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-31.
C. Coolant Recovery Tank. SeeCooling System on
page 5-24.
D. Automatic Transmission Fluid Dipstick.
See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-21.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-20.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-34.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-36.
J. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-35.Engine Oil
For diesel engine vehicles, see “Engine Oil” in the
DURAMAX®Diesel manual.
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-14
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If this is not done, the
oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-15
To inspect or replace the engine air cleaner/filter, do the
following:
1. Unhook the retainer clips and remove the cover.
2. Lift the filter out of the engine air cleaner/filter
housing. Care should be taken to dislodge as
little dirt as possible.
3. Clean the engine air cleaner/filter housing.
4. Inspect or replace the engine air cleaner/filter.
Make sure that the filter fits properly into the
housing.
5. Reinstall the cover and fasten the retaining clips.
{CAUTION:
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 helps to stop
flames if the engine backfires. If it is not there and
the engine backfires, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/filter off.Notice:If the air cleaner/ lter is off, a back re
can cause a damaging engine re. And, dirt
can easily get into the engine, which will damage it.
Always have the air cleaner/ lter in place when
you are driving.
Automatic Transmission Fluid
If your vehicle has the DURAMAX Diesel engine, see
the DURAMAX Diesel manual for more information.
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission fluid listed inRecommended
Fluids and Lubricants on page 6-14.
5-21
How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission uid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
•When outside temperatures are above 90°F (32°C).
•At high speed for quite a while.
•In heavy traffic — especially in hot weather.
•While pulling a trailer.To get the right reading, the fluid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C), drive
the vehicle in D (DRIVE) until the engine temperature
gage moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine run
at idle for five minutes if outside temperatures are 50°F
(10°C) or more. If it is colder than 50°F (10°C), you may
have to idle the engine longer. Should the fluid level be
low during this cold check, you must check the fluid hot
before adding fluid. Checking the fluid hot will give you a
more accurate reading of the fluid level.
5-22
How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. SeeRecommended
Fluids and Lubricants on page 6-14.
Using a funnel, add fluid down the transmission dipstick
tube only after checking the transmission fluid while it is
hot. A cold check is used only as a reference. If the fluid
level is low, add only enough of the proper fluid to bring
the level up to the HOT area for a hot check. It does not
take much fluid, generally less than one pint (0.5 L).
Do not overfill.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages may
not be covered by the vehicle’s warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-14.
•After adding fluid, recheck the fluid level as described
under “How to Check Automatic Transmission Fluid,”
earlier in this section.
•When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle down
to lock the dipstick in place.
Cooling System
If your vehicle has a diesel engine, see “Van Models”
under “Cooling System” in the DURAMAX®Diesel
Supplement.
The Cooling System allows the engine to maintain the
correct working temperature.
A. Radiator Pressure Cap
B. Coolant Recovery Tank
C. Engine Cooling Fan(s)
5-24
ApplicationCapacities
English Metric
Fuel Tank
Standard Tank (Passenger and Cargo) 31.0 gal 117.3 L
Standard Tank (Cab and Chassis) 33.0 gal 124.9 L
Optional Tank (Cab and Chassis)* 57.0 gal 215.7 L
* 159 inch (4 039 mm) wheelbase or 177 inch (4 496 mm) wheelbase only
Transmission Fluid
4-SPD 4L60-E 5.0 qt 4.7 L
4-SPD 4L80-E (Standard and Heavy Duty) 7.7 qt 7.3 L
Wheel Nut Torque 140 ft lb 190Y
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck fluid level after filling.
Engine Speci cations
Engine VIN Code Transmission Spark Plug Gap
4.3L V6 X Automatic 0.060 in (1.52 mm)
4.8L V8 C Automatic 0.040 in (1.01 mm)
5.3L V8 4 Automatic 0.040 in (1.01 mm)
6.0L V8 K Automatic 0.040 in (1.01 mm)
5-111
Recommended Fluids and
Lubricants
This maintenance section applies to vehicles with a
gasoline engine. If your vehicle has a diesel engine, see
the maintenance schedule section in the DURAMAX
®
Diesel manual.
Fluids and lubricants identified below by name, part
number, or specification can be obtained from your
dealer/retailer.
Usage Fluid/Lubricant
Engine OilEngine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certified for Gasoline Engines
starburst symbol. To determine the
proper viscosity for your vehicle’s
engine, seeEngine Oil on
page 5-15.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant on
page 5-25.
Usage Fluid/Lubricant
Hydraulic Brake
SystemDOT 3 Hydraulic Brake Fluid
(GM Part No. U.S. 12377967, in
Canada 89021320).
Windshield
WasherOptikleen
®Washer Solvent.
Parking Brake
Cable GuidesChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Power Steering
SystemGM Power Steering Fluid
(GM Part No. U.S. 89021184, in
Canada 89021186).
Automatic
TransmissionDEXRON
®-VI Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Chassis
LubricationChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
6-14
Usage Fluid/Lubricant
Front Wheel
BearingsWheel bearing lubricant
meeting requirements of
NLGI #2, Category GC or GC-LB
(GM Part No. U.S. 1051344, in
Canada 993037).
Front and
Rear AxleSAE 75W-90 Synthetic
Axle Lubricant
(GM Part No. U.S. 89021677,
in Canada 89021678) or equivalent
meeting GM Specification 9986115.
Transfer CaseDEXRON
®-VI Automatic
Transmission Fluid.
One-Piece
Propshaft Slip
Yoke Spline,
Two-Piece
Propshaft
Slip-in-Tube
SplineSpline Lubricant, Special Lubricant
(GM Part No. U.S. 12345879, in
Canada 10953511) or lubricant
meeting requirements of
GM 9985830.
Usage Fluid/Lubricant
Hood HingesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningWeatherstrip Lubricant
(GM Part No. U.S. 3634770,
in Canada 10953518) or
Dielectric Silicone Grease
(GM Part No. U.S. 12345579,
in Canada 992887).
Weatherstrip
SqueaksSynthetic Grease
with Teflon, Superlube
(GM Part No. U.S. 12371287,
in Canada 10953437).
6-15