GMC SONOMA 1999 Owner's Manual

Long Trip/Highway Scheduled Maintenance
7-39
82,500 Miles (137 500 km)

Change engine oil and filter (or every 12 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 12 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)

Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
90,000 Miles (150 000 km)

Change engine oil and filter (or every 12 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 12 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)

For Two
-Wheel-Drive vehicles only: Clean and repack the front wheel
bearings (or at each brake relining, whichever occurs first).

Change automatic transmission fluid and filter 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.
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

Long Trip/Highway Scheduled Maintenance
7-40
± 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).

Replace fuel filter.
An Emission Control Service. (See footnote
.)
Replace engine air cleaner filter.
An Emission Control Service.
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
97,500 Miles (162 500 km)
Change engine oil and filter (or every 12 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 12 months, whichever occurs first).
(See footnote #.)
Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)ACTUAL
SERVICED BY:MILEAGE
DATE

Long Trip/Highway Scheduled Maintenance
7-41
100,000 Miles (166 000 km)

Inspect spark plugwires.
An Emission Control Service.

Replace spark plugs.
An Emission Control Service.

If you haven't used your vehicle under severe service conditions listed
previously and, therefore, haven't changed your automatic transmission fluid,
change both the fluid and filter. Manual transmission fluid doesn't
require change.

4.3L V6 Engine Only: Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)

Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See ªEngine Coolantº in the Index for what to use.
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
the cooling system and pressure cap.
An Emission Control Service.
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

7-42
Part B: Owner Checks and Services
Listed in this part are owner checks and services which
should be performed at the intervals specified to help
ensure the safety, dependability and emission control
performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any fluids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown in
Part D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel fill.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. See ªEngine Oilº in the Index for
further details.Engine Coolant Level Check
Check the engine coolant level and add DEX
-COOL

coolant mixture if necessary. See ªEngine Coolantº in
the Index for further details.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the
windshield washer tank and add the proper fluid if
necessary. See ªWindshield Washer Fluidº in the Index
for further details.
At Least Once a Month
Tire Inflation Check
Make sure tires are inflated to the correct pressures.
Don't forget to check your spare tire. See ªTiresº in the
Index for further details.
Cassette Deck Service
Clean cassette deck. Cleaning should be done every
50 hours of tape play. See ªAudio Systemsº in the Index
for further details.

7-43 At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages are
working properly. Look for any other loose or damaged
safety belt system parts. If you see anything that might
keep a safety belt system from doing its job, have it
repaired. Have any torn or frayed safety belts replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag system
does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace blade
inserts that appear worn or damaged or that streak or
miss areas of the windshield. Also see ªWiper Blades,
Cleaningº in the Index.Spare Tire Check
At least twice a year, after the monthly inflation check
of the spare tire determines that the spare is inflated to
the correct tire inflation pressure, make sure that the
spare tire is stored securely. Push, pull, and then try to
rotate or turn the tire. If it moves, use the wheel wrench
to tighten the cable. See ªStoring the Spare Tire and
Toolsº in the Index.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. (See ªRecommended Fluids and Lubricantsº in
the Index.)
Manual Transmission Check
Check the transmission fluid level; add if needed. See
ªManual Transmission Fluidº in the Index. Check for
leaks. A fluid leak is the only reason for fluid loss. Have
the system inspected and repaired if needed.

7-44
Automatic Transmission Check
Check the transmission fluid level; add if needed. See
ªAutomatic Transmission Fluidº in the Index. A fluid
loss may indicate a problem. Check the system and
repair if needed.
Hydraulic Clutch System Check
Check the fluid level in the clutch reservoir. See
ªHydraulic Clutch Fluidº in the Index. A fluid loss in
this system could indicate a problem. Have the system
inspected and repaired at once.
At Least Four Times a Year
Tailgate Lubrication Service
Lubricate tailgate latch bolt, handle assembly pivot points,
and hinges with lubricant recommended in Part D.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part D.
Body Lubrication Service
Lubricate all body door and fuel door hinges, latches
and locks including the glove box, console doors, the
body hood, secondary latch, pivots, spring anchor,
release pawl, and any moving seat hardware. Lubricate
the hood safety lever pivot and prop rod pivot. Part D
tells you what to use. More frequent lubrication may be
required when exposed to a corrosive environment.

7-45
Starter Switch Check
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake (see ªParking
Brakeº in the Index if necessary) and the regular brake.
NOTE: Do not use the accelerator pedal, and be
ready to turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only in
PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push the clutch down halfway
and try to start the engine. The starter should work
only when the clutch is pushed down all the way to
the floor. If the starter works when the clutch isn't
pushed all the way down, your vehicle needs service.Automatic Transmission Shift Lock Control
System Check
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough
room around the vehicle. It should be parked on a
level surface.
2. Firmly apply the parking brake (see ªParking Brakeº
in the Index if necessary).
NOTE: Be ready to apply the regular brake
immediately if the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try to move the shift lever out of
PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.

7-46
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.

With an automatic transmission, the key should turn
to LOCK only when the shift lever is in PARK (P).

With a manual transmission, the key should turn to
LOCK only when you press the key release button.
On all vehicles, the key should come out only in LOCK.
Parking Brake and Automatic Transmission
PARK (P) Mechanism Check
CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in case
it begins to roll. Be ready to apply the regular
brake at once should the vehicle begin to move.
Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.

To check the parking brake's holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.

To check the PARK (P) mechanism's holding ability:
With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.

7-47
Part C: Periodic
Maintenance Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall). You should let your dealer's
service department or other qualified service center do
these jobs. Make sure any necessary repairs are
completed at once.
Proper procedures to perform these services may be
found in a service manual. See ªService and Owner
Publicationsº in the Index.
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook
-up, binding, leaks,
cracks, chafing, etc. Clean and then inspect the drive
axle boot seals for damage, tears or leakage. Replace
seals if necessary.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out
-of-position parts as well as open seams,
holes, loose connections or other conditions which could
cause a heat build
-up in the floor pan or could let
exhaust fumes into the vehicle. See ªEngine Exhaustº in
the Index.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes, fittings
and clamps; replace as needed. Clean the outside of the
radiator and air conditioning condenser. To help ensure
proper operation, a pressure test of the cooling system and
pressure cap is recommended at least once a year.

7-48 Throttle System Inspection
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts as
needed. Replace any components that have high effort
or excessive wear. Do not lubricate accelerator and
cruise control cables.
Drive Axle Service
Check rear/front axle fluid level and add as needed.
Check constant velocity joints and axle seals for leaking.
Transfer Case
(Four-Wheel Drive) Inspection
Every 12 months or at oil change intervals, check front
axle and transfer case and add lubricant when necessary.
Check vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off
-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Also inspect drum brake linings
for wear and cracks. Inspect other brake parts, including
drums, wheel cylinders, calipers, parking brake, etc.
Check parking brake adjustment. You may need to have
your brakes inspected more often if your driving habits
or conditions result in frequent braking.