2010 GMC YUKON DENALI brake fluid

Checking Things Under
the Hood
{WARNING:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
{WARNING:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, 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.
Hood Release
To open the hood:
1. Pull the handle withthis symbol on it. It is
located inside the
vehicle to the lower left
of the steering wheel.
6-12

A.Engine Air Cleaner/Filter on page 6‑20.
B. Coolant Surge Tank and Pressure Cap. See Cooling System on page 6‑26.
C. Remote Positive (+) Terminal. See Jump Starting
on page 6‑42.
D. Battery on page 6‑41.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
under Engine Oil on page 6‑15.
F. Automatic Transmission Dipstick (Out of View). See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 6‑22.
G. Remote Negative (−) Terminal (GND) (Out of View). See Jump Starting on page 6‑42.
H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 6‑15.
I. Engine Cooling Fan (Out of View). See Cooling
System on page 6‑26.
J. Power Steering Fluid Reservoir (Out of View). See Power Steering Fluid on page 6‑36.
K. Brake Master Cylinder Reservoir. See “Brake
Fluid” under Brakes on page 6‑38.
L. Underhood Fuse Block on page 6‑111.
M. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on
page 6‑37.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
See Engine Compartment Overview
on page 6‑14for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If this is not done,
the oil dipstick might not show the actual level.
2. 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.
6-15

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice:Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑11.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance
on page 7‑3. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricantson
page 7‑11.
How to Check Automatic Transmission
Fluid
Notice: Too much or too little fluid can damage your
transmission. Too much can mean that some of the
fluid could come out and fall on hot engine parts or
exhaust system parts, starting a fire. Too little fluid
could cause the transmission to overheat. Be sure
to get an accurate reading if you check your
transmission fluid.
Before checking the fluid level, prepare the vehicle as
follows:
1. Start the engine and park the vehicle on a level surface. Keep the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever through each gear range, pausing for about
three seconds in each range. Then, move the shift
lever back to P (Park).
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4. Allow the engine to idle (500–800 rpm) for at least
one minute. Slowly release the brake pedal.
5. Keep the engine running and press the Trip/Fuel button or trip odometer reset stem until TRANS
TEMP (Transmission Temperature) displays on the
Driver Information Center (DIC).
6. Using the TRANS TEMP reading, determine and perform the appropriate check procedure. If the
TRANS TEMP reading is not within the required
temperature ranges, allow the vehicle to cool,
or operate the vehicle until the appropriate
transmission fluid temperature is reached.
Cold Check Procedure
Use this procedure only as a reference to determine
if the transmission has enough fluid to be operated
safely until a hot check procedure can be made.
The hot check procedure is the most accurate
method to check the fluid level. Perform the hot
check procedure at the first opportunity. Use this cold check procedure to check fluid level when
the transmission temperature is between 80°F and 90°F
(27°C and 32°C).
1. Locate the
transmission dipstick at
the rear of the engine
compartment, on the
passenger side of the
vehicle.
See Engine Compartment Overview
on page 6‑14for more information.
2. Flip the handle up and then pull out the dipstick and wipe it with a clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way, wait three seconds, and then pull it back out again.
4. Check both sides of the dipstick and read the lower level. Repeat the check procedure to verify the
reading.
6-23

Brakes
Brake Fluid
The brake master cylinder
reservoir is filled with
DOT 3 brake fluid. See
Engine Compartment
Overview
on page 6‑14for the location of the
reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down:
.The brake fluid level goes down because of normal
brake lining wear. When new linings are installed,
the fluid level goes back up.
.A fluid leak in the brake hydraulic system can also
cause a low fluid level. Have the brake hydraulic
system fixed, since a leak means that sooner or
later the brakes will not work well. Do not top off the brake fluid. Adding fluid does not
correct a leak. If fluid is added when the linings are
worn, there will be too much fluid when new brake
linings are installed. Add or remove brake fluid, as
necessary, only when work is done on the brake
hydraulic system.
{WARNING:
If too much brake fluid is added, it can spill on
the engine and burn, if the engine is hot enough.
You or others could be burned, and the vehicle
could be damaged. Add brake fluid only when
work is done on the brake hydraulic system.
See
“Checking Brake Fluid” in this section.
When the brake fluid falls to a low level, the brake
warning light comes on. See Brake System Warning
Light on page 4‑32.
Refer to the Maintenance Schedule to determine when
to check the brake fluid. See Scheduled Maintenance
on page 7‑3.
6-38

Checking Brake Fluid
Check brake fluid by looking at the brake fluid reservoir.
SeeEngine Compartment Overview on page 6‑14.
The fluid level should be
above MIN. If it is not,
have the brake hydraulic
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
Use only new DOT 3 brake fluid from a sealed
container. See Recommended Fluids and Lubricantson
page 7‑11. Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This helps keep dirt
from entering the reservoir.
{WARNING:
With the wrong kind of fluid in the brake hydraulic
system, the brakes might not work well. This could
cause a crash. Always use the proper brake fluid.
Notice:
.Using the wrong fluid can badly damage
brake hydraulic system parts. For example,
just a few drops of mineral-based oil, such
as engine oil, in the brake hydraulic system
can damage brake hydraulic system parts
so badly that they will have to be replaced.
Do not let someone put in the wrong kind
of fluid.
.If brake fluid is spilled on the vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on the vehicle. If you do, wash it off
immediately. See Washing Your Vehicle
on
page 6‑102
.
6-39

When the Change Engine Oil Soon message displays,
certain services, checks, and inspections are required.
The services described for MaintenanceIshould be
performed at every engine oil change. The services
described for Maintenance IIshould be
performed when:
.Maintenance Iwas performed the last time the
engine oil was changed.
.It has been 10 months or more since the Change
Engine Oil Soon message has displayed or since
the last service.
Maintenance I
.Change engine oil and filter. See Engine Oilon
page 6‑15. An Emission Control Service.
.Engine coolant level check. See Engine Coolanton page 6‑27.
.Windshield washer fluid level check. See
Windshield Washer Fluid on page 6‑37.
.Tire inflation check. SeeInflation - Tire Pressureon page 6‑64.
.Tire wear inspection. See Tire Inspection and
Rotation on page 6‑71.
.Rotate tires. See Tire Inspection and Rotationon
page 6‑71.
.Fluids visual leak check (or every 12 months,
whichever occurs first). A leak in any system
must be repaired and the fluid level checked.
.Engine air cleaner filter inspection (vehicles
driven in dusty conditions only). See Engine
Air Cleaner/Filter on page 6‑20.
.Brake system inspection (or every 12 months,
whichever occurs first).
Maintenance II
.Perform all services described in Maintenance I.
.Steering and suspension inspection. Visual
inspection for damaged, loose, or missing parts or
signs of wear.
.Lubricate the front suspension, steering linkage,
and parking brake cable guides. Control arm ball
joints are maintenance‐free.
.Engine cooling system inspection. Visual
inspection of hoses, pipes, fittings, and clamps
and replacement, if needed.
7-4

Once a Year
.Starter switch check. SeeOwner Checks and
Services on page 7‑9.
.Parking brake and automatic transmission P (Park)
mechanism check. See Owner Checks and
Services on page 7‑9.
.Automatic transmission shiftlock control system
check. See Owner Checks and Serviceson
page 7‑9.
.Ignition transmission lock check. See Owner
Checks and Services on page 7‑9.
.Hood and liftgate gas strut support service.
Visually inspect gas strut for signs of wear,
corrosion, cracks, loss of lubricant, or other
damage. Check the hold open ability of gas strut.
Replace as necessary with genuine parts from
your dealer/retailer.
.Engine cooling system and pressure cap pressure
check. Radiator and air conditioning condenser
outside cleaning. See Cooling System
on
page 6‑26.
.Exhaust system and nearby heat shields
inspection for loose or damaged components.
.Accelerator pedal check for damage, high effort,
or binding. Replace if needed.
First Engine Oil Change After Every
40 000 km/25,000 Miles
.Fuel system inspection for damage or leaks.
First Engine Oil Change After Every
80 000 km/50,000 Miles
.Engine air cleaner filter replacement. See Engine
Air Cleaner/Filter on page 6‑20.
.Automatic transmission fluid change (severe
service) for vehicles mainly driven in heavy city
traffic in hot weather, in hilly or mountainous
terrain, when frequently towing a trailer, or used for
taxi, police, or delivery service. See Automatic
Transmission Fluid on page 6‑22.
.Transfer case fluid change (severe service) for
vehicles mainly driven when frequently towing a
trailer, or used for taxi, police, or delivery service.
Check vent hose at transfer case for kinks and
proper installation. Check to be sure vent hose is
unobstructed, clear, and free of debris. During any
maintenance, if a power washer is used to clean
mud and dirt from the underbody, care should be
taken to not directly spray the transfer case output
seals. High pressure water can overcome the
seals and contaminate the transfer case fluid.
Contaminated fluid will decrease the life of the
transfer case and should be replaced.
7-6