1999 GMC YUKON Owner's Manual

Long Trip/Highway Scheduled Maintenance
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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 +.)
100,000 Miles (166 000 km)

Inspect spark plug wires. An Emission Control Service.

Replace spark plugs. An Emission Control Service.

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.
± In hilly or mountainous terrain.
± When doing frequent trailer towing.
± Uses such as found in taxi, police or delivery service.
(Continued)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

Long Trip/Highway Scheduled Maintenance
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100,000 Miles (166 000 km) (Continued)

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.

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

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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.
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.
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.

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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.
Air Cleaner Filter Restriction Indicator Check
Your vehicle has an indicator on the engine that lets you
know when the air cleaner filter is dirty and needs to be
changed. Check indicator at least twice a year or when
your oil is changed, whichever occurs first. See ªAir
Cleanerº in the Index for more information. Inspect your
air cleaner filter restriction indicator more often if the
vehicle is used in dusty areas or under off road conditions.
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.)Automatic Transmission Check
Check the transmission fluid level; add if needed. See
ªAutomatic Transmissionº in the Index. A fluid loss may
indicate a problem. Check the system and repair if needed.
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 hood and body door hinges, body
door hinge pins, hood latch assembly, secondary latch,
pivots, spring anchor, and release pawl, rear
compartment hinges, tailgate hinge, tailgate linkage,
outer tailgate handle pivot points, latches, fuel door, fuel
door hinge, locks and folding seat hardware. Part D tells
you what to use. More frequent lubrication may be
required when exposed to a corrosive environment.

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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. 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.Brake
-Transmission Shift Interlock (BTSI) 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's BTSI
needs service.

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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.

The key should turn to LOCK only when the shift
lever is in PARK (P).

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 all brakes.
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.

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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 and Suspension 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.
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.
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.

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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.