2004 GMC SONOMA maintenance

4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P), or
REVERSE (R) for a manual transmission.
5. If you have a four-wheel-drive vehicle with an
automatic transfer case, be sure the transfer case is
in a drive gear–not in NEUTRAL.
6. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
•start your engine,
•shift into a gear, and
•release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. SeePart A: Scheduled Maintenance
Services on page 6-4for more on this. Things that are
especially important in trailer operation are automatic
transmission fluid (don’t overfill), engine oil, axle
lubricant, belt, cooling system and brake system. Each
of these is covered in this manual, and the Index
will help you find them quickly. If you’re trailering, it’s a
good idea to review these sections before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-63

Tire Chains..................................................5-74
If a Tire Goes Flat........................................5-74
Changing a Flat Tire.....................................5-75
Compact Spare Tire......................................5-85
Appearance Care............................................5-86
Cleaning the Inside of Your Vehicle.................5-86
Care of Safety Belts......................................5-89
Weatherstrips...............................................5-89
Cleaning the Outside of Your Vehicle..............5-89
Sheet Metal Damage.....................................5-91
Finish Damage.............................................5-92
Underbody Maintenance................................5-92
Chemical Paint Spotting.................................5-92
Vehicle Care/Appearance Materials..................5-93Vehicle Identication......................................5-94
Vehicle Identification Number (VIN).................5-94
Service Parts Identification Label.....................5-94
Electrical System............................................5-94
Add-On Electrical Equipment..........................5-94
Headlamps..................................................5-95
Windshield Wiper Fuses................................5-95
Power Windows and Other Power Options.......5-95
Fuses and Circuit Breakers............................5-95
Capacities and Specications........................5-101
Section 5 Service and Appearance Care
5-2

Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you will go to your dealer
for all your service needs. You will get genuine GM parts
and GM-trained and supported service people.
We hope you will want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Doing Your Own Service Work
If you want to do some of your own service work, you
will want to use the proper service manual. It tells you
much more about how to service your vehicle than this
manual can. To order the proper service manual, see
Service Publications Ordering Information on page 7-11.
Your vehicle has an air bag system. SeeServicing
Your Air Bag-Equipped Vehicle on page 1-52before
attempting to do your own service work.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeePart E: Maintenance Record on page 6-36.
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
CAUTION: (Continued)
5-3

Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:
•Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures
are below freezing.
•Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
•You frequently tow a trailer or use a carrier on top
of your vehicle.
•The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months — whichever
occurs first.
If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months — whichever
occurs first. Driving a vehicle with a fully warmed engine
under highway conditions will cause engine oil to
break down slower.
5-16

Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12for
more information on the location of the engine air
cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter every 15,000 miles (25 000
km) and replace every 30,000 miles (50 000 km). If
you are driving in dusty/dirty conditions, inspect the filter
at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To remove either engine air cleaner/filter, do the
following:
1. Remove the fasteners that hold the cover on and
remove the cover
2. Lift out the engine air cleaner/filter, if needed.
3. Insert a new air filter. SeeNormal Maintenance
Replacement Parts on page 6-34to determine
which filter to use.
4. Reinstall the engine air cleaner/filter cover. Tighten
the fasteners to hold the cover in place.
5-18

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it helps to
stop ame if the engine backres. If it is not
there and the engine backres, you could be
burned. Do not drive with it off, and be careful
working on the engine with the air cleaner/
lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
Automatic Transmission Fluid
When to Check and Change the
Automatic Transmission Fluid
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 15,000 miles
(25 000 km) if the vehicle is mainly driven under one or
more of these conditions:
•In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
•In hilly or mountainous terrain.
•When doing frequent trailer towing.
•Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter every 50,000 miles
(83 000 km).
SeePart A: Scheduled Maintenance Services on
page 6-4.
5-19

4. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a hot
check.
5. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. SeePart D:
Recommended Fluids and Lubricants on page 6-32.
Add fluid 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 doesn’t take much fluid, generally less than one pint
(0.5 L). Don’t overfill.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III is
not covered by your new vehicle warranty.
•After adding fluid, recheck the fluid level as
described under “How to Check the Automatic
Transmission Fluid” earlier.
•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.
5-22

Brakes
Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the
brake fluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the fluid level goes back up. The other reason is
that fluid 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 will not
work well, or will not work at all.
So, it is not a good idea to “top off” your brake fluid.
Adding brake fluid will not correct a leak. If you add fluid
when your linings are worn, then you will have too
much fluid when you get new brake linings. You should
add (or remove) brake fluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid 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 brake fluid. SeePart C: Periodic
Maintenance Inspections on page 6-30.
5-37