Page 294 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 293the full cold mark. If it is not, there
may be a leak in the cooling
system.
If coolant is visible but the coolant
level is not at or above the full cold
mark, see “ How to Add Coolant to
the Coolant Surge Tank, ” following.
How to Add Coolant to the
Coolant Surge Tank
{ WarningSpilling coolant on hot engine
parts can burn you. Coolant
contains ethylene glycol and it will
burn if the engine parts are hot
enough.
{ Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
(Continued) Warning (Continued) warning. The engine could catch
fire and you or others could be
burned.
{ WarningSteam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
(Continued) Caution (Continued) cause system damage. If coolant
is not visible in the surge tank,
contact your dealer.
If no coolant is visible in the surge
tank, add coolant.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap
slowly, and remove it.
Page 308 of 425
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 307
LED Lighting This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Fog Lamps
To replace the front fog lamp bulb:
1. Locate the fog lamp under the
front bumper.
2. Disconnect the electrical
connector from the fog lamp
bulb assembly by pressing the
connector release.
3. Turn the bulb counterclockwise
to remove it from the housing. Back-Up Lamps To replace a back-up bulb:
1. Open the liftgate. See Liftgate
0 43 .
2. Remove the taillamp closeout
cover from the lamp assembly
by pulling rearward from the
top and bottom at the same
time to unfasten the snap tabs. 3. Remove the two screws from
the taillamp assembly.
4. Pull the taillamp assembly
straight back to remove.
Page 309 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
308 Vehicle Care 5. Turn the bulb socket
counterclockwise to remove it
from the taillamp assembly.
6. Pull the bulb straight out from
the socket.
7. Put a new bulb into the socket,
insert it into the taillamp
assembly, and turn the bulb
socket clockwise until it clicks.
8. Reinstall the taillamp assembly
and tighten the screws.
9. Reinstall the taillamp cover by
snapping it into place. License Plate Lamp
Passenger Side Shown, Driver
Side Similar
1. Bulb Socket 2. Bulb
3. Lamp Assembly
To replace one of these bulbs:
1. Push the lamp assembly (3)
toward the center of the
vehicle.
2. Pull the lamp assembly down
to remove.
3. Turn the bulb socket (1)
counterclockwise to remove it
from the lamp assembly (3).
4. Pull the bulb (2) straight out of
the bulb socket (1).
5. Push the replacement bulb
straight into the bulb socket
and turn the bulb socket
clockwise to install it into the
lamp assembly.
6. Push the lamp assembly back
into position until the release
tab locks into place.
Page 344 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 343
1. Pull to open the trim
panel door.
The third row driver side seat
may need to be folded to
access the trim panel door.
2. Lift the acoustic pad to access
the jack and tools.
3. Turn the wing nut retaining the
tool bag (3) counterclockwise to
remove it.
Pull the tool bag toward the
front of the vehicle and lift the
rear portion of the bag upward
to remove it. 4. Turn the jack knob (1)
counterclockwise to release the
jack and wheel blocks from the
bracket.
5. Turn the wing nut retaining the
wheel blocks (2)
counterclockwise to remove the
wheel blocks and the wheel
block retainer.
Use the following tools:
1. Jack
2. Wheel Blocks
3. Jack Handle
4. Jack Handle Extensions
5. Wheel Wrench To access the spare tire, refer to the
following graphics and instructions:
1. Hoist Assembly
2. Hoist Shaft
3. Hoist Shaft Access
Cover/Hole
4. Jack Handle Extensions
5. Wheel Wrench
6. Spare Tire Lock
7. Hoist End of Extension Tool
8. Hoist Shaft Access Hole
9. Spare Tire (Valve Stem
Pointed Down)
10. Tire/Wheel Retainer
11. Hoist Cable
Page 345 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
344 Vehicle Care 1. Open the hoist shaft access
door (3) on the bumper to
access the spare tire lock (6).
If equipped with a hitch cover,
turn the hitch cover retainers
counterclockwise and pull the
cover downward to remove it
before removing the hoist shaft
access door.
2. To remove the spare tire lock
(6), insert the ignition key, turn
it clockwise and then pull it
straight out. 3. Assemble the two jack handle
extensions (4) and wheel
wrench (5), as shown. 4. Insert the open end of the
extension (7) through the hole
in the rear bumper (8) (hoist
shaft access hole).
Be sure the hoist end of the
extension (7) connects to the
hoist shaft. The ribbed square
end of the extension is used to
lower the spare tire.
5. Turn the wheel wrench
counterclockwise to lower the
spare tire to the ground.
Continue to turn the wheel
wrench until the spare tire can
be pulled out from under the
vehicle.
Page 346 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 3456. Use the wheel wrench hook to
pull the hoist cable closer to
assist in reaching the
spare tire.
7. Tilt the tire toward the vehicle
with some slack in the cable to
access the tire/wheel retainer.
Tilt the retainer and pull it and
the cable and spring through
the center of the wheel.
Once the retainer is separated
from the guide pin, tilt the
retainer and pull it through the
center of the wheel along with
the cable and latch.
8. Put the spare tire near the
flat tire. Removing the Flat Tire and
Installing the Spare Tire 1. Do a safety check before
proceeding. See If a Tire Goes
Flat 0 341 for more information.
2. If the vehicle has a center cap
that covers the wheel
fasteners, place the chisel end
of the wheel wrench in the slot
on the wheel and gently pry the
cap out.
If the wheel has a bolt-on hub
cap, loosen the plastic nut caps
by turning the wheel wrench
counterclockwise. The plastic
nut caps will be retained in the
hub cap after it is removed
from the wheel. 3. Use the wheel wrench to
loosen all the wheel nuts. Turn
the wheel wrench
counterclockwise to loosen the
wheel nuts. Do not remove the
wheel nuts yet.
Page 347 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
346 Vehicle Care
Jacking Locations (Overall View)
4. Position the jack under the
vehicle, as shown.
Left Front Shown, Right Front
Similar
Front Tire Flat: If the flat tire is
on a front tire of the vehicle,
use the jack handle and only one jack handle extension.
Attach the wheel wrench to the
jack handle extension. Attach
the jack handle to the jack.
Position the jack on the frame
behind the flat tire where the
frame sections overlap. Turn
the wheel wrench clockwise to
raise the vehicle. Raise the
vehicle far enough off the
ground so there is enough
room for the spare tire to clear
the ground.
Rear Position
Rear Tire Flat: If the flat tire is
on a rear tire of the vehicle,
use the jack handle (2) and both jack handle
extensions (3). Attach the
wheel wrench (4) to the jack
handle extensions (3). Attach
the jack handle (2) to the
jack (1). Use the jacking
pad (5) provided on the rear
axle. Turn the wheel wrench (4)
clockwise to raise the vehicle.
Raise the vehicle far enough
off the ground so there is
enough room for the spare tire
to clear the ground.
{ WarningGetting under a vehicle when it is
lifted on a jack is dangerous.
If the vehicle slips off the jack,
you could be badly injured or
killed. Never get under a vehicle
when it is supported only by
a jack.
Page 348 of 425

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 347
{ WarningRaising the vehicle with the jack
improperly positioned can
damage the vehicle and even
make the vehicle fall. To help
avoid personal injury and vehicle
damage, be sure to fit the jack lift
head into the proper location
before raising the vehicle.
5. Remove all of the wheel nuts.
6. Take off the flat tire. 7. Remove any rust or dirt from
the wheel bolts, mounting
surfaces, and spare wheel.
{ WarningRust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, a cloth or a paper
(Continued) Warning (Continued) towel can be used; however, use
a scraper or wire brush later to
remove all rust or dirt.
8. Put the wheel nuts back on
with the rounded end of the
nuts toward the wheel after
mounting the spare tire.
{ WarningNever use oil or grease on bolts
or nuts because the nuts might
come loose. The vehicle's wheel
could fall off, causing a crash.
9. Tighten each wheel nut by
hand. Then use the wheel
wrench to tighten the nuts until
the wheel is held against
the hub.
10. Turn the wheel wrench
counterclockwise to lower the
vehicle. Lower the jack
completely.