brake fluid CADILLAC CT4 2021 User Guide

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
304 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 305
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 305
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 306
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 306
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 306
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 309
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 312
Engine Oil Life System . . . . . . . . . . . 314
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Engine Air Filter Life System . . . . 315
Engine Air Cleaner/Filter . . . . . . . . . 316
Cooling System . . . . . . . . . . . . . . . . . . . 317
Engine Overheating . . . . . . . . . . . . . . 322
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 323
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . . . . . . 324
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 325
Battery - North America . . . . . . . . . 326
All-Wheel Drive . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 329
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 330
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
Front Turn Signal Lamps . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 330
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 334
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
All-Season Tires . . . . . . . . . . . . . . . . . . 339
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 340
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 340
Self-Sealing Tires . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 341
Summer Tires . . . . . . . . . . . . . . . . . . . . 341
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 343
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 344
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . 348
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . 352
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 352
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Buying New Tires . . . . . . . . . . . . . . . . 354
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Uniform Tire Quality Grading . . . 356
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 357

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
310 VEHICLE CARE
1. Windshield Washer Fluid Reservoir.See Washer Fluid 0323.
2. Engine Coolant Surge Tank and Pressure Cap. See Cooling System
0 317.
3. Engine Air Cleaner/Filter 0316.
4. Engine Cooling Fan (Out of View). See Cooling System 0317.
5. Engine Oil Fill Cap. See Engine Oil
0 312.
6. Engine Oil Dipstick. See Engine Oil
0 312.
7. Remote Positive (+) Battery Terminal. See Jump Starting - North
America 0366.
8. Brake Fluid Reservoir. See Brake
Fluid 0325.
9. Remote Negative (-) Battery Terminal. See Jump Starting - North
America 0366.
10. Engine Compartment Fuse Block
0332.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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312 VEHICLE CARE
9. Brake Fluid Reservoir. SeeBrake
Fluid 0325.
10. Remote Negative (-) Battery Terminal. See Jump Starting - North
America 0366.
11. Engine Compartment Fuse Block. See Engine Compartment Fuse Block
0 332.
Engine Oil
To ensure proper engine performance
and long life, careful attention must
be paid to engine oil. Following these
simple, but important steps will help
protect your investment:
.Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil” in
this section.
.Check the engine oil level regularly
and maintain the proper oil level.
See “Checking Engine Oil” and
“When to Add Engine Oil” in this
section.
.Change the engine oil at the
appropriate time. See Engine Oil Life
System 0314.
.Always dispose of engine oil
properly. See “What to Do with Used
Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially prior
to a long trip. The engine oil dipstick
handle is a loop. See Engine
Compartment Overview 0309 for the
location.
{Warning
The engine oil dipstick handle may
be hot; it could burn you. Use a
towel or glove to touch the dipstick
handle.
If a low oil Driver Information Center
(DIC) message displays, check the oil
level.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the
engine oil level after the engine has
been off for at least two hours.
Checking the engine oil level on
steep grades or too soon after
engine shutoff can result in incorrect readings. Accuracy
improves when checking a cold
engine prior to starting. Remove the
dipstick and check the level.
.If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the engine
is not warm. Pull out the dipstick,
wipe it with a clean paper towel or
cloth, then push it back in all the
way. Remove it again, keeping the
tip down, and check the level.
When to Add Engine Oil
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See
“Selecting the Right
Engine Oil” later in this section for an

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VEHICLE CARE 323
back on, continue to drive normally
and have the cooling system checked
for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.
Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. SeeEngine Compartment
Overview 0309 for reservoir location.
Caution
.Do not use washer fluid that
contains any type of water
repellent coating. This can cause
the wiper blades to chatter
or skip.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system and
paint.
.Do not mix water with
ready-to-use washer fluid. Water
can cause the solution to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
(Continued)
Caution (Continued)
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank if
it is completely full.
Brakes
Disc brake linings have built-in wear
indicators that make a high-pitched
warning sound when the brake linings
are worn and new linings are needed.
The sound can come and go or can be
heard all the time when the vehicle is
moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will not
work well. That could lead to a
crash. When the brake wear
warning sound is heard, have the
vehicle serviced.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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VEHICLE CARE 325
How to Disable the Brake Pad
Life System
The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear
sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn can still determine when the
pads should be replaced. SeeBrakes
0 323.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC)
(Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.
2. Select DISABLE.
To turn the brake pad life system back
on, follow the above steps but select
ENABLE in Step 2.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 4 brake
fluid as indicated on the reservoir cap.
See Engine Compartment Overview
0 309 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
.Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
.A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well. Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
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 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.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning Light
0 99.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
326 VEHICLE CARE
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid at
the specified intervals to prevent
increased stopping distance. See
Maintenance Schedule0380.
What to Add
Use only GM approved DOT 4 brake
fluid from a clean, sealed container.
See Recommended Fluids and
Lubricants 0391.
{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the paint
finish can be damaged. Immediately
wash off any painted surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove the
cap and do not add fluid.
Refer to the replacement number
shown on the original battery label
when a new battery is needed.
The vehicle has an Absorbed Glass
Mat (AGM) 12-volt battery.
Installation of a standard 12-volt
battery will result in reduced 12-volt
battery life.
When using a 12-volt battery charger
on the 12-volt AGM battery, some
chargers have an AGM battery setting
on the charger. If available, use the
AGM setting on the charger, to limit
charge voltage to 14.8 volts. Follow
the charger manufacturer's
instructions.
Stop/Start System
This vehicle has a Stop/Start system
to shut off the engine to help
conserve fuel. See Stop/Start System
0 221.{Warning
WARNING: Battery posts,
terminals, and related accessories
contain lead and lead compounds,
chemicals known to the State of
California to cause cancer and birth
defects or other reproductive harm.
Batteries also contain other
chemicals known to the State of
California to cause cancer. WASH
HANDS AFTER HANDLING. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition 65 Warning
0 305 and the back cover.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode. You
can be badly hurt if you are not
(Continued)

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VEHICLE CARE 327
Warning (Continued)
careful. SeeJump Starting - North
America 0366 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the black,
negative (−) cable from the battery to
keep the battery from running down.
Extended Storage: Remove the black,
negative (−) cable from the battery or
use a battery trickle charger.
All-Wheel Drive
If the vehicle is equipped with
All-Wheel-Drive (AWD), this is an
additional system that needs
lubrication.
Transfer Case
Under normal driving conditions,
transfer case fluid does not require
maintenance unless there is a fluid
leak or unusual noise. If required,
have the transfer case serviced by
your dealer.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and
property could be damaged. Make
sure there is room in front of the
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 the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park) mechanism's
holding ability: With the engine
running, shift to P (Park). Then
release the parking brake followed
by the regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear and cracking. See
Maintenance Schedule 0380.
Replacement blades come in different
types and are removed in different
ways. For proper type and length, see
Maintenance Replacement Parts 0392.
Caution
Allowing the wiper arm to touch
the windshield when no wiper blade
is installed could damage the
windshield. Any damage that occurs
would not be covered by the vehicle
warranty. Do not allow the wiper
arm to touch the windshield.

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374 VEHICLE CARE
Caution
To avoid surface damage on wheels
and wheel trim, do not use strong
soaps, chemicals, abrasive polishes,
cleaners, or brushes. Use only GM
approved cleaners. Do not drive the
vehicle through an automatic car
wash that uses silicon carbide tire/
wheel cleaning brushes. Damage
could occur and the repairs would
not be covered by the vehicle
warranty.
Brake System
Visually 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. Inspect drum brake linings/
shoes for wear or cracks. Inspect all
other brake parts.
Steering, Suspension, and
Chassis Components
Visually inspect steering, suspension,
and chassis components for damaged,
loose, or missing parts or signs of
wear at least once a year.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
Body Component Lubrication
Lubricate all key lock cylinders, hood
hinges, liftgate hinges, and the steel
fuel door hinge, unless the
components are plastic. Applying
silicone grease on weatherstrips with a
clean cloth will make them last
longer, seal better, and not stick or
squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any corrosive
materials from the underbody. Take
care to thoroughly clean any areas
where mud and other debris can
collect.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate
the fluid. Contaminated fluid will
decrease the life of the transfer case
and/or axles and should be replaced
Sheet Metal Damage
If the vehicle is damaged and requires
sheet metal repair or replacement,
make sure the body repair shop
applies anti-corrosion material to
parts repaired or replaced to restore
corrosion protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.
Finish Damage
Quickly repair minor chips and
scratches with touch-up materials
available from your dealer to avoid
corrosion. Larger areas of finish
damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting
Airborne pollutants can fall upon and
attack painted vehicle surfaces
causing blotchy, ring-shaped
discolorations, and small, irregular

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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SERVICE AND MAINTENANCE 379
Service and
Maintenance
General Information
General Information . . . . . . . . . . . . . 379
Maintenance Schedule
Maintenance Schedule . . . . . . . . . . . 380
Special Application Services
Special Application Services . . . . . 388
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . . . . . . . 388
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . 391
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
Maintenance Records
Maintenance Records . . . . . . . . . . . . 394
General Information
Your vehicle is an important
investment. This section describes the
required maintenance for the vehicle.
Follow this schedule to help protect
against major repair expenses
resulting from neglect or inadequate
maintenance. It may also help to
maintain the value of the vehicle if it
is sold. It is the responsibility of the
owner to have all required
maintenance performed.
Your dealer has trained technicians
who can perform required
maintenance using genuine
replacement parts. They have
up-to-date tools and equipment for
fast and accurate diagnostics. Many
dealers have extended evening and
Saturday hours, courtesy
transportation, and online scheduling
to assist with service needs.
Your dealer recognizes the importance
of providing competitively priced
maintenance and repair services. With
trained technicians, the dealer is the
place for routine maintenance such as
oil changes and tire rotations and additional maintenance items like
tires, brakes, batteries, and wiper
blades.
Caution
Damage caused by improper
maintenance can lead to costly
repairs and may not be covered by
the vehicle warranty. Maintenance
intervals, checks, inspections,
recommended fluids, and lubricants
are important to keep the vehicle in
good working condition.
Do not have chemical flushes that
are not approved by GM performed
on the vehicle. The use of flushes,
solvents, cleaners, or lubricants that
are not approved by GM could
damage the vehicle, requiring
expensive repairs that are not
covered by the vehicle warranty.
The Tire Rotation and Required
Services are the responsibility of the
vehicle owner. It is recommended to
have your dealer perform these
services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to

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SERVICE AND MAINTENANCE 381
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the
vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System0314.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0352.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0312 and
Engine Oil Life System 0314.
.If equipped, check the air filter
life percentage. If necessary, replace
the engine air filter and reset the
engine air filter life system. See
Engine Air Filter Life System 0315.
If the vehicle is not equipped with
the engine air filter life system,
inspect the engine air cleaner filter.
See Engine Air Cleaner/Filter 0316.
.Check engine coolant level. See
Cooling System 0317.
.Check windshield washer fluid level.
See Washer Fluid 0323.
.Check tire inflation pressures. See
Tire Pressure 0346.
.Inspect tire wear. See Tire Inspection
0 352.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0370.
.Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0370.
.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.