2004 BUICK CENTURY radiator

When the engine is cold,
the coolant level should be
at or above the COLD
mark on the coolant
recovery tank. If it is not,
there may be a leak
at the pressure cap or in
the radiator hoses,
heater hoses, radiator,
water pump, or somewhere
else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them. If
you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine is overheating, both fans should be
running. If they are not the vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
“Overheated Engine Protection Operating Mode”
in the Index for information on driving to a safe
place in an emergency.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-29

How to Add Coolant to the Coolant
Recovery Tank
If a problem has not been found yet, but the coolant
level is not at the COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®engine
coolant at the coolant recovery tank. SeeEngine
Coolant on page 5-22for more information.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
5-30

When the coolant in the coolant recovery tank is at the
COLD mark, start the vehicle.
If the overheated engine warnings continue, there is
one more thing that can be done. Add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before this is done.
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator
pressure cap — even a little — they can come
out at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to turn the pressure cap.
5-31

How to Add Coolant to the Radiator
Notice:Your engine has a specic radiator
ll procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.
Remove the radiator pressure cap when the cooling
system, including the radiator pressure cap and upper
radiator hose, is no longer hot.
1. Turn the pressure cap slowly counterclockwise at
its rst stop. Do not press down while turning the
pressure cap.If a hiss is heard, wait for it to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap, but now push down
as you turn it. Remove the pressure cap.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
5-32

3. After the engine cools, open the coolant air bleed
valves. There are two bleed valves.
One is located on the
thermostat housing.
The other is located on the
thermostat bypass tube.4. Fill the radiator with the
proper DEX-COOL®
coolant mixture,
up to the base of the
ller neck. See
Engine Coolant on
page 5-22for more
information about the
proper coolant mixture.
If a stream of coolant is coming from an air bleed
valve, close the valve. Otherwise, close the
valves after the radiator is lled.
5. Rinse or wipe any spilled coolant from the engine
and the compartment.
5-33

6. Then ll the coolant recovery tank to the COLD
mark on the coolant recovery tank.
7. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.8. Start the engine and let it run until the upper
radiator hose feels it is getting hot. Watch out for the
engine cooling fans.
9. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
5-34

Maintenance Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts or
signs of wear. Inspect power steering lines and
hoses for proper hook-up, binding, leaks, cracks,
chang, etc.
(c)Visually inspect hoses and have them replaced if
they are cracked, swollen or deteriorated. Inspect
all pipes, ttings and clamps; replace with genuine
GM parts as needed. To help ensure proper operation,
a pressure test of the cooling system and pressure
cap and cleaning the outside of the radiator and
air conditioning condenser is recommended at least
once a year.(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)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. 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.)
(f)Lubricate all key lock cylinders. Lubricate all hinges
and latches, including those for the body doors,
hood, secondary latch, pivots, spring anchor, release
pawl, rear compartment, glove box door and console
door. More frequent lubrication may be required
when exposed to a corrosive environment. Applying
silicone grease on weatherstrips with a clean cloth will
make them last longer, seal better and not stick or
squeak.
(g)If you drive regularly under dusty conditions, the
lter may require replacement more often.
6-7

(h)Change automatic transaxle uid and lter 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.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-22for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)Check 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 or
cruise control cables.
(k)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the uid level checked. Add uid if needed.Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability and emission control performance of your
vehicle. Your GM Goodwrench dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-12.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13for further
details.
Notice:It is important to check your oil regularly
and keep it at the proper level. Failure to keep your
engine oil at the proper level can cause damage
to your engine not covered by your warranty.
6-8