2003 GMC SAVANA brake

Trailer Wiring Harness
The optional heavy-duty trailer wiring package includes
a seven-wire harness assembly at the rear of the
vehicle and a four-wire harness assembly under the
left hand side of the instrument panel. The seven-wire
harness assembly is taped together and located in
a frame pocket at the driver side rear left corner of the
frame. The seven-wire harness includes a 30-amp
feed wire. Both harnesses come without connectors and
should be wired by a qualied electrical technician.
The technician can use the following color code chart
when connecting the wiring harness to your trailer
and trailer brake controller.Seven-Wire HarnessLight Green: Back-up lamps
Brown: Parking lamps
Yellow: Left stoplamp and turn signal
Dark Green: Right stoplamp and turn signal
Dark Blue: Use for electric trailer brakes
Orange: Trailer accessory
White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
Black: Ground
Red/White Stripe: Fused Battery
Dark Blue: Trailer Brake Feed
Light Blue: Fused Stop/CHMSL
4-46
2003 - Savana OM

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of
Your Vehicle..............................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specifications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood.....................5-9
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-17
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-25
Engine Overheating.......................................5-26
Cooling System
............................................5-28
Engine Fan Noise
.........................................5-34
Power Steering Fluid
.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
All-Wheel Drive..............................................5-46
Rear Axle.......................................................5-47
Front Axle......................................................5-48
Noise Control System.....................................5-49
Tampering with Noise Control System
Prohibited.................................................5-49
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps..................................................5-50
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-52
Taillamps.....................................................5-52
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-55
Tires..............................................................5-56
Inflation – Tire Pressure................................5-57
Dual Tire Operation.......................................5-58
Tire Inspection and Rotation...........................5-58
When It Is Time for New Tires.......................5-60
Section 5 Service and Appearance Care
5-1
2003 - Savana OM

Filling a Portable Fuel Container
{CAUTION:
Neverfill a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
•Dispense gasoline only into approved
containers.
•Do notfill a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed or
on any surface other than the ground.
•Bring thefill nozzle in contact with the
inside of thefill opening before operating
the nozzle. Contact should be maintained
until thefilling is complete.
•Don’t smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start afire. These include liquids like fuel,
oil, coolant, brakefluid, windshield washer and
otherfluids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-9
2003 - Savana OM

A. Battery
B. Radiator Pressure Cap
C. Coolant Recovery Tank
D. Transmission Fluid Dipstick
E. Engine Oil Fill
F. Engine Oil Dipstick
G. Air Filter Restriction Indicator
H. Engine Air Cleaner/Filter
I. Power Steering Reservoir
J. Brake Master Cylinder
K. Windshield Washer Fluid
Engine Oil
Checking Engine Oil
It’s a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.The engine oil dipstick has
a yellow handle and is
located near the center of
the engine compartment.
SeeEngine Compartment
Overview on page 5-12
for more information
on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.
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.
5-13
2003 - Savana OM

To get the right reading, thefluid should be at normal
operating temperature, which is 180°Fto200°F
(82°Cto93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C).Ifit’s colder than 50°F (10°C), drive the vehicle
in DRIVE (D) until the engine temperature gage
moves and then remains steady for 10 minutes.
A coldfluid 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 forfive minutes if outside temperatures are
50°F (10°C) or more. If it’s colder than 50°F (10°C), you
may have to idle the engine longer. Should thefluid
level be low during this cold check, youmustcheck the
fluid hot before addingfluid. Checking thefluid hot
will give you a more accurate reading of thefluid level.Checking the Fluid Level
Prepare your vehicle as follows:
•Park your vehicle on a level place. Keep the engine
running.
•With the parking brake applied, place the shift lever
in PARK (P).
•With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
•Let the engine run at idle for three minutes or more.
5-20
2003 - Savana OM

Power Steering Fluid
The power steeringfluid reservoir is located in the
engine compartment on the driver’s side of the vehicle.
When to Check Power Steering Fluid
It is not necessary to regularly check power steeringfluid
unless you suspect there is a leak in the system or
you hear an unusual noise. Afluid 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 thefluid level on the dipstick.
The level should be at the COLD FILL mark.
If necessary, add only enoughfluid to bring the
level up to the mark.
To prevent contamination of brakefluid, never check or
fill the power steering reservoir with the brake master
cylinder cover off.
What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-18.
Always use the properfluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
5-35
2003 - Savana OM

Brakes
Brake Fluid
Your brake master cylinder reservoir isfilled with DOT-3
brakefluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brakefluid level
in the reservoir might go down. Thefirst is that the brake
fluid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, thefluid
level goes back up.The other reason is thatfluid is leaking out of the brake
system. If it is, you should have your brake system
fixed, since a leak means that sooner or later your
brakes won’t work well, or won’t work at all.
So, it isn’t a good idea to“top off”your brakefluid.
Adding brakefluid won’t correct a leak. If you addfluid
when your linings are worn, then you’ll have too
muchfluid when you get new brake linings. You should
add (or remove) brakefluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brakefluid, it can spill on
the engine. Thefluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See“Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brakefluid. SeePart C: Periodic
Maintenance Inspections on page 6-16.
5-37
2003 - Savana OM

Checking Brake Fluid
You can check the brake
fluid without taking off
the cap.
Just look at the brakefluid reservoir. Thefluid level
should be above MIN. If it isn’t, have your brake system
checked to see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
What to Add
When you do need brakefluid, use only DOT-3 brake
fluid. Use new brakefluid from a sealed container
only. SeePart D: Recommended Fluids and Lubricants
on page 6-18.Always clean the brakefluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind offluid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brakefluid.
Notice:
•Using the wrongfluid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they’ll have to be replaced.
Don’t let someone put in the wrong kind offluid.
•If you spill brakefluid on your vehicle’s painted
surfaces, the paintfinish can be damaged.
Be careful not to spill brakefluid on your
vehicle. If you do, wash it off immediately.
See“Appearance Care”in the Index.
5-38
2003 - Savana OM