1994 CHEVROLET SUBURBAN Owners Manual

What to Use
use a mixture of one-half clean water (preferably distilled) and one-half
antifreeze that meets
“GM Specification 6038-M,” which won’t damage
aluminum
parts. You can also use a recycled coolant conforming to “GM
Specification 6038-M” with a complete coolant flush and refill. If you use
this mixture, you don’t need
to add anything else.
NOTICE:
If you use an improper coolant mix, your engine could overheat
and be badly damaged. The repair cost wouldn’t be covered by
your warranty.
TOO much water in the mix can freeze and crack
the engine, radiator, heater core and other parts.
Some conditions, such as air trapped in the cooling system, can affect the
coolant level in the radiator. Check the coolant level when the engine is cold
and follow the steps under “Adding Coolant” for
the proper way to add
coolant.
If you have to add coolant more than four times a year, have your dealer
check your cooling system.
NOTICE:
If you use the proper coolant, you don’t have to add extra
inhibitors
or additives which claim to improve the system. These
can be harmful.
6-36
ProCarManuals.com

Adding Coolant -Gas Engines
The coolant recovery
tank is located on the
passenger side at the
rear comer of the
engine compartment
To Check Coolant
When your engine is cold, the coolant level should be at COLD, or a little
higher. When your engine
is warm, the level should be up to HOT, or a little
higher.
To Add Coolant
If you need more coolant, add the proper mix at the coolant recovery tank.
Add coolant mix at the recovery tank, but be careful not to spill it.
6-37
ProCarManuals.com

Adding Coolant -Diesel Engines
.. The coolant surge tank
is located on the
passenger side at the
rear corner
of the
engine compartment
To Check Coolant
When your engine is cold, the coolant level should be at the COLD mark,
or
a little higher. When your engine is warm, the level should be above the
COLD mark.
If this light comes on,
it means you're low
on engine coolant.
To Add Coolant
If you need more coolant, add the proper mix ut the surge tank, but only
when the
engine is cool.
Open the bleed valve
on the thermostat housing to allow trapped air out of
the system. Close the bleed valve when coolant begins to flow out.
6-38
ProCarManuals.com

Radiator Pressure Cap-Gas Engines
I I
The radiator pressure
cap must be tightly
installed with the
arrows on the cap
lined up with the
ovefflow tube on the
radiator filler neck.
NOTICE:
Your radiator cap is a 15 psi (105 kPa) pressure-type cap and
must be tightly installed
to prevent coolant loss and possible
engine damage from overheating. Be sure the arrows on the cap
line up with the overflow tube on the radiator filler neck.
ProCarManuals.com

Surge Tank Pressure Cap- Diesel Engines
The surge tank
pressure cap must be
tightly installed with
the arrows
on the cap
lined up with the top
tube
of the coolant
surge tank.
NOTICE:
Your surge tank pressure cap 1s a unique 15 psi (105 kPa)
pressure-type cap for use with surge tank cooling systems only.
It must be tightly installed to prevent coolant loss and possible
engine damage from overheating. Be sure the arrows on the cap
line up with the top tube
of the coolant surge tank.
Thermostat
Engine coolant temperature is controlled by a thermostat in the engine
coolant system. The thermostat stops the flow
of coolant through the
radiator until the coolant reaches a preset temperature.
When you replace your thermostat, an
AC@ thermostat is recommended.
Power Steering Fluid
I NOTICE:
Always turn the engine off before checking or adding power
steering
fluid. The power steering pump cap is close to the fan
and other moving parts.
6-40
ProCarManuals.com

How To Check Power Steering Fluid
l
Unscrew the cap and
wipe the dipstick with
a clean rag. Replace
the cap and
completely tighten it.
Then remove the cap
again and look
at the
fluid level on the
dipstick.
0 When the engine
compartment is
hot, the level
should
be at the
FULL mark.
When the engine
compartment is
cool, the
level
should be at the
FULL COLD
mark.
Whaf fo Add
Refer to the Maintenance Schedule to determine what kind of fluid to use.
See “Recommended Fluids and Lubricants” in the Index.
NOTICE:
When adding power steering fluid or making a complete fluid
change, always
use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and
seals.
6-41
ProCarManuals.com

Hydro-Boost Brake System (Hydraulic Pump)
The power steering pump is also used as the Hydro-boost pump. Refer to
“Power Steering System” in this section when checking fluid level
or
adding fluid.
Windshield Washer Fluid
To Add
Open the cap labeled
“WASHER
FLUID
ONLY.” Add washer
fluid until the bottle is
full.
~ NOTICE:
0 When using concentrated washer fluid, follow the
manufacturer’s instructions for adding water.
Don’t mix water with ready-to-use washer fluid. Water can
cause the solution to freeze and damage your washer fluid
tank and other parts of the washer system. Also, water
doesn’t clean as well
as washer fluid.
Fill your washer fluid tank only 3/4 full when it’s very cold.
This allows for expansion, which could damage the tank
if it is
completely full.
Don’t use radiator antifreeze in your windshield washer. It
can damage your washer system and paint.
ProCarManuals.com

Brakes
Brake Master Cylinder
4 Your brake master
cylinder
is here. It is
filled with
DOT-3
brake fluid.
There are only two reasons why the brake fluid level in your master cylinder
might go down. The first is that the brake fluid goes down to an acceptable
level during normal brake lining wear. When new linings are put in, the
fluid level goes back up. The other reason is that fluid is leaking out
of the
brake system. If it is,
you should have your brake system fixed, since a leak
means that sooner or later your brakes won’t work well, or won’t work at
all.
So, it isn’t a good idea to “top off’ your brake fluid. Adding brake fluid
won’t correct
a leak. If you add fluid when your linings are worn, then
you’ll have too much fluid when you get new brake linings. You should add
(or remove) brake fluid, as necessary, only when work is done on the brake
hydraulic system.
Refer to the Maintenance Schedule to determine when to check your brake
fluid. See “Periodic Maintenance Inspections” in the Index.
ProCarManuals.com