2004 CHEVROLET EXPRESS CARGO VAN steering

Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages. So
you may hear an increase in fan noise. This is
normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down
when additional cooling is not required and the clutch
partially disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
Power Steering Fluid
The power steering uid reservoir is located in the
engine compartment on the driver’s side of the vehicle.
SeeEngine Compartment Overview on page 5-12
for more information on location.
5-36

When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then
remove the cap again and look at the uid level on the
dipstick.The level should be at the COLD FILL mark. If necessary,
add only enough uid to bring the level up to the mark.
To prevent contamination of brake uid, never check or
ll the power steering reservoir with the brake master
cylinder cover off.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 6-12.
Always use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses and seals.
5-37

Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to its
width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.
Cold Ination Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeInation - Tire Pressure on page 5-66.Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the U.S.
Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identication
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-33.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-33.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-33.
Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
There are 6.9 kPa’s to one psi.
5-64

If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially if you maintain your tires properly. If air goes
out of a tire, it’s much more likely to leak out slowly.
But if you should ever have a “blowout,” here are a few
tips about what to expect and what to do:
If a front tire fails, the at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use
in a skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if possible.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
The jack provided with your vehicle is
designed only for changing a at tire. If it is
used for anything else, you or others could be
badly injured or killed if the vehicle slips off
the jack. Use the jack provided with your
vehicle only for changing a at tire.
If a tire goes at, the next part shows how to use your
jacking equipment to change a at tire safely.
5-75

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. Reset oil life system. SeeEngine Oil on
page 5-13.An Emission Control Service.••
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner lter or change indicator (if equipped). If necessary,
replace lter. SeeEngine Air Cleaner/Filter on page 5-18.An Emission Control
Service. See footnote †.••
Rotate tires and check ination pressures and wear. SeeTires on page 5-58.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
Perform any needed additional services. See “Additional Required Services” in
this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
Inspect shields (vehicles with GVWR above 10,000 lbs. only).See footnote (g).•
Inspect throttle system.See footnote (m).•
6-5

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(41 500)50,000
(83 000)75,000
(125 000)100,000
(166 000)125,000
(207 500)150,000
(240 000)
Engine cooling system service (or
every 5 years, whichever occurs
rst).An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.•
Inspect evaporative control system.
An Emission Control Service. See
footnotes † and (k).•••
Maintenance Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
#Lubricate the front suspension, kingpin bushings,
steering linkage and rear driveline center splines.(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts,
signs of wear or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, chang, etc.
6-7

Usage Fluid/Lubricant
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
®-III 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.
Front Wheel
BearingsWheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037).
Usage Fluid/Lubricant
Front and Rear
AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261, in Canada 10953455) or
equivalent meeting GM Specication
9986115.
Transfer CaseDEXRON
®-III 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.
Hood HingesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningDielectric Silicone Grease (GM Part
No. U.S. 12345579, in Canada
992887).
Weatherstrip
SqueaksSynthetic Grease with Teon,
Superlube (GM Part No. U.S.
12371287, in Canada 10953437).
6-13

Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle, suspension,
brakes, electrical, steering, body, etc.
RETAIL SELL PRICE: $120.00
Transmission, Transaxle, Transfer
Case Unit Repair Manual
This manual provides information on unit repair service
procedures, adjustments, and specications for 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.
In Canada, information pertaining to Product Service
Bulletins can be obtained by contacting your General
Motors dealer or by calling 1-800-GM-DRIVE
(1-800-463-7483).
Owner’s Information
Owner publications are written specically 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: $35.00
Without Portfolio: Owner’s Manual only.
RETAIL SELL PRICE: $25.00
7-12