Coolant Replacement - Chevrolet 1979 Light Duty Truck Owner's Manual

Cooling System Care
It is not usually necessary to remove the radiator cap to check the
coolant level. Lift the hood and look at the "see through" coolant
recovery tank. This should
fuel stops. When the engine is cold, the coolant level should be at or
slightly above the "Cold Level" mark on the tank. When the engine
has fully warmed up, the level should be at or slightly below the "Cold
Level" mark on the tank. If the coolant level is low, remove the cap
on the coolant recovery tank. Add enough of a 50/50 mixture of a good
quality ethylene glycol (antifreeze) and water to the tank to bring the
level up to the proper mark. Reinstall the cap on the tank.
There are conditions which can happen, such as air being trapped in
the system, that may affect the coolant level in the radiator: It is
recommended that the. coolant level in the radiator
periodic intervals such as at the time of engine oil changes when the
engine is cold. Follow steps l , 8, 9, and lO of the following section
"Coolant Replacement" for radiator cap removal and coolant addition
method.
If coolant has to be added more than four times a year either to the
recovery tank or to the radiator, see your dealer for a cooling system
check.
NOTICE: If the proper quality antifreeze is used, there is no need to add
extra inhibitors or additives that claim to improve the system. They may
be harmful to the proper operation of the system.
Coolant System Service
The cooling system should be serviced at the time/mileage specified
in Section A of the Maintenance Schedule folder as follows:
l . Wash the radiator cap and filler neck with clean water. See step
l of "Coolant Replacement" to remove radiator cap.
Check the coolant level in the radiator and have it tested for freeze
2.
.protection. Add ethylene glycol antifreeze, if needed, to maintain
the specified freeze protection.
3. Have the cooling system and radiator cap tested for a pressure
capacity of 15 psi (lOS kPa). If a replacement cap is needed, use
an AC-Delco cap, or an equivalent cap, designed for coolant
recovery systems and specified for your model.
Tighten all radiator and heater hose clamps and inspect all hoses.
4.
Replace the hoses if they are swollen, "checked," or otherwise
worn.
5. Clean the front of the radiator core and air conditioning condenser
to remove dirt and other objects. Also clean the auxiliary engine
and/or transmission oil cooler if the vehicle has them.

Coolant Replacement

At the time/mileage specified in Section A of the Maintenance
Schedule folder, the cooling system should be flushed and refilled as
follows:
l .
Remove the radiator cap when the engine is cool:
•
Tum the cap slowly to the left until it reaches a "stop." (Do
not press down while turning the cap.)
be
done at regular intervals, such as during
5-7
be
checked at