Chevrolet Corvette 1963 Repair & Tune-Up Manual page 24

20 GENERAL INFORMATION AND MAINTENANCE
pump or other areas, indicate possible leak-
age, which must be corrected before filling
die system with fresh coolant.
CHECK THE RADIATOR CAP
While you are checking me coolant level, also
check the condition of the radiator cap gasket
and the seal inside of the cap (if your vehicle
uses a coolant recovery system). The radiator
cap is designed to seal the cooling system un-
der normal operating conditions which allows
the system to build-up a certain amount of
pressure (this pressure rating is stamped or
printed on the cap). The pressure in the sys-
tem raises the boiling point of the coolant to
help prevent overheating. If the radiator cap
does not seal, the boiling point of the coolant
is lowered and overheating will occur. If the
cap must be replaced, purchase the new cap
according to the type of system you have (with
or without a coolant recovery tank) and the
pressure rating which is specified for your ve-
hicle.
CLEAN RADIATOR OF DEBRIS
Periodically clean any debris—leaves, paper,
insects, etc.—from the radiator fins. Pick the
large pieces off by hand. The smaller pieces
can be washed away with water pressure from
a hose.
Carefully straighten any bent radiator fins
with a pair of needle nose pliers. Be careful—
the fins are very soft. Don't wiggle the fins
back and forth too much. Straighten them
once and try not to move them again.
DRAIN AND REFILL THE COOLING
SYSTEM
Completely draining and refilling the cooling
system every two years at least will remove
accumulated rust, scale and other deposits.
Coolant in late model cars is a 50-50 mixture
of ethylene glycol and water for year round
SEAL
Check the radiator cap's rubber gasket and metal
seal for deterioration at least once a year
use. Use a good quality antifreeze with water
pump lubricants, rust inhibitors and other
corrosion inhibitors along with acid neutral-
izers.
1. Drain the existing antifreeze and cool
ant. Open the radiator and engine drain pet-
cocks, or disconnect die bottom radiator hose,
at the radiator outlet.
NOTE: Before opening the radiator pet-
cock, spray it with some penetrating lubri-
cant.
2. Close the petcock or re-connect the
lower hose and fill the system with water.
3. Add a can of quality radiator flush.
4. Idle the engine until the upper radia
tor hose gets hot.
5. Drain the system again.
6. Repeat this process until the drained
water is clear and free of scale.
7. Close all petcocks and connect all the
hoses.
8. If equipped widi a coolant recovery
system, flush die reservoir witii water and
leave empty.
9. Determine die capacity of your cool
ing system (see capacities specifications). Add
a 50/50 mix of quality antifreeze (ethylene
glycol) and water to provide die desired pro
tection.
10. Run die engine to operating tempera
ture.
11. Stop die engine and check die coolant
level.
12. Check die level of protection with an
anti-freeze tester, replace die cap and check
for leaks.
Air Conditioning
SAFETY PRECAUTIONS
There are two particular hazards associated
widi air conditioning systems and diey bodi
relate to die refrigerant gas.
First, die refrigerant gas is an extremely
GASKET cold substance. When exposed to air, it will
instantly freeze any surface it comes in con-
tact widi, including your eyes. The odier
hazard relates to fire. Ahhough normally non-
toxic, refrigerant gas becomes highly poison-
ous in die presence of an open flame. Inha-
lation of die vapor formed by burning refrig-
erant can be fetal. Keep all forms of fire
(including cigarettes) well clear of die air-
conditioning system.
Any repair work to an air conditioning sys-
tem should be left to a professional. Do not,
under any circumstances, attempt to loosen