2004 CHEVROLET CORVETTE radiator cap

How to Check and Add Fluid
Fluid should be added if the fluid level is below the step
on the inside of the reservoir. There are additional
instructions on the reservoir cap. Put the rubber seal
and cap back on. SeeEngine Compartment Overview
on page 5-12for more information on location.
Engine Coolant
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-26.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
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.
5-23

{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark. The FULL COLD mark is on the front
of the coolant surge tank. Do not overfill the surge tank.
Too much coolant can result in an overflow when the
fluid is hot.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank,but only when the
engine is cool.
{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.
When replacing the pressure cap, make sure it is
hand-tight.
5-25

The coolant level should be at or above the FULL COLD
mark. If it is not, you may have 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.
CAUTION: (Continued)
CAUTION: (Continued)
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, your 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.
5-30

1. Park the vehicle on a level surface. You can
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-quarter turn and
then stop.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
2. Then keep turning the pressure cap slowly, and
remove it.3. Then fill the coolant surge tank with the proper
mixture, to the FULL COLD mark on the coolant
surge tank.
5-33

4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan(s).
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD mark on
the coolant surge tank.5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
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 and body door
hinges.Lubricate all hinges and latches, including those
for the hood, rear compartment, console door and
any folding seat hardware. 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)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.
6-7

(h)Change automatic transmission 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.
-Uses such as high performance operation.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-23for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and filler neck.
Pressure test the cooling system and pressure cap.
Owner Checks and Services
These owner checks and services should be performed
at the intervals specified 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 fluids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-11.
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.
Engine Coolant Level Check
Check the engine coolant level and add
DEX-COOL®coolant mixture if necessary. SeeEngine
Coolant on page 5-23for further details.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the windshield
washer tank and add the proper fluid if necessary.
6-8