Page 350 of 528
Black plate (38,1)Cadillac STS Owner Manual - 2011
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
.Start the engine
.Shift into a gear
.Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual's Maintenance Schedule or
Index for more information. Things that are especially
important in trailer operation are automatic transmission
fluid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect these
before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. See Engine Overheating
on page 6‑30.
5-38
Page 372 of 528

Black plate (22,1)Cadillac STS Owner Manual - 2011
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the scheduled
maintenance intervals and replace it at the first oil
change after each 80 000 km (50,000 mile) interval. See
Scheduled Maintenance
on page 7‑3for more
information. If you are driving in dusty/dirty conditions,
inspect the filter at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter remove the filter from the
vehicle and lightly shake the filter to release loose dust
and dirt. If the filter remains caked with dirt, a new filter
is required.
To inspect or replace the filter:
1. Remove the two screws located on the top of the cover.
2. Disconnect the coolant recovery hose so that it is not going across the top of the engine air cleaner/
filter.
3. Loosen the clamp and remove the duct from the passenger's side of the engine air cleaner/filter. 4. The two sides of the airbox are hinged at the
bottom. Open the airbox by pushing the top of the
airbox cover toward the engine.
5. Remove the air filter by lifting it straight up through the opening in the airbox.
6. Inspect or replace the engine air cleaner/filter. See Maintenance Replacement Parts
on page 7‑11for
the correct part number for the filter.
7. Reinstall the cover by reversing Steps 1 through 4.
{WARNING:
Operating the engine with the air cleaner/filter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
flames if the engine backfires. Use caution when
working on the engine and do not drive with the
air cleaner/filter off.
Notice: If the air cleaner/filter is off, dirt can easily
get into the engine, which could damage it. Always
have the air cleaner/filter in place when you are
driving.
6-22
Page 373 of 528

Black plate (23,1)Cadillac STS Owner Manual - 2011
Automatic Transmission Fluid
How to Check Automatic Transmission
Fluid
It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid
loss. If a leak occurs, take the vehicle to the dealer
service department and have it repaired as soon as
possible.
The vehicle is not equipped with a transmission fluid
level dipstick. There is a special procedure for checking
and changing the transmission fluid. Because this
procedure is difficult, it should be done at the dealer
service department. Contact the dealer for additionalinformation or the procedure can be found in the service
manual. To purchase a service manual, see
Service
Publications Ordering Information on page 8‑17.
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 7‑9.
Change the fluid and filter at the intervals listed in
Scheduled Maintenance
on page 7‑3, and be sure
to use the fluid listed in Recommended Fluids and
Lubricants on page 7‑9.
6-23
Page 386 of 528

Black plate (36,1)Cadillac STS Owner Manual - 2011
What to Add
DOT 3 brake fluid is recommended. DOT 4 brake fluid
is also compatible with the vehicle's brake system parts.
However, if DOT 4 fluid is used, it is recommended that
the brake hydraulic system be flushed and refilled with
new DOT 4 fluid at a regular maintenance service every
two years. SeeScheduled Maintenance
on page 7‑3.
Use new brake fluid from a sealed container only. See
Recommended Fluids and Lubricants on page 7‑9.
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 6‑109
.
Brake Wear
This vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched
warning sound when the brake pads are worn and new
pads are needed. The sound can come and go or be
heard all the time the vehicle is moving, except when
applying the brake pedal firmly.
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Page 394 of 528
Black plate (44,1)Cadillac STS Owner Manual - 2011
How to Check Lubricant
A. Drain Plug
B. Fill Plug
To get an accurate reading, the vehicle should be on a
level surface. If the level is below the bottom of the filler plug hole,
located on the transfer case, you'll need to add some
lubricant. Add enough lubricant to raise the level to the
bottom of the filler plug hole. Use care not to
overtighten the plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See
Recommended Fluids and
Lubricants on page 7‑9.
Rear Axle
When to Check Lubricant
It is not necessary to regularly check rear axle fluid
unless you suspect there is a leak or you hear an
unusual noise. A fluid loss could indicate a problem.
Have it inspected and repaired.
6-44
Page 395 of 528
Black plate (45,1)Cadillac STS Owner Manual - 2011
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
located on the rear axle, you'll need to add some
lubricant. Add enough lubricant to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids and
Lubricants on page 7‑9.
Front Axle
When to Check and Change Lubricant
It is not necessary to regularly check the front axle fluid
unless you suspect there is a leak or you hear an
unusual noise. A fluid loss could indicate a problem.
Have it inspected and repaired.
6-45
Page 396 of 528
Black plate (46,1)Cadillac STS Owner Manual - 2011
How to Check Lubricant
A. Drain Plug
B. Filler Plug
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
located on the front axle, you may need to add some
lubricant.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Recommended Fluids and
Lubricants on page 7‑9.
Headlamp Aiming
Headlamp aim has been preset at the factory and
should need no further adjustment.
However, if your vehicle is damaged in a crash, the
headlamp aim may be affected. Aim adjustment to the
low-beam headlamps may be necessary if oncoming
drivers flash their high-beam headlamps at you (for
vertical aim).
If the headlamps need to be re-aimed, it is
recommended that you take the vehicle to your dealer
for service.
6-46
Page 399 of 528
Black plate (49,1)Cadillac STS Owner Manual - 2011
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking. SeeScheduled Maintenance on page 7‑3.
It's a good idea to clean or replace the wiper blade
assembly on a regular basis or when worn. For proper
windshield wiper blade length and type, see
Maintenance Replacement Parts on page 7‑11.
To replace the wiper blade assembly, do the following: 1. Pull the windshield wiper assembly away from the windshield.
2. Squeeze the tabs on each side of the wiper bladeassembly and slide the assembly off the end of the
wiper arm.
3. Replace the blade assembly with a new one.
Allowing the wiper blade arm to touch the
windshield when no wiper blade is installed could
damage the windshield. Any damage that occurs
would not be covered by your warranty. Do not
allow the wiper blade arm to touch the windshield.
4. Repeat the steps for the other wiper.
6-49