Aluminum Radiator Service - GMC G Service Manual

6B2-18 RADIATOR

ALUMINUM RADIATOR SERVICE

The aluminum/plastic radiator can be repaired at the
dealership. The following components are easily replaced:
• Core
• Tanks and gaskets
• Oil coolers and gaskets
• Drain cock and gasket
The tanks cannot be repaired if broken or cracked. The
radiator core can be replaced and the new core used with
the original tanks and oil cooler.
PRECAUTIONS
As with all cooling system service, take measures to
prevent personal injury and damage to the system.
CAUTION: To help avoid the danger of being
burned, do not remove the radiator cap while the
engine and radiator are still hot. Scalding fluid
and steam can be blown out under pressure if
the cap is taken off too soon.
NOTICE: DO NOT USE " BOIL O U T TANKS OR
VATS. Common service methods for copper or
brass radiators may destroy an aluminum radia­
tor. Do not use caustic or lye cleaning solutions
for aluminum radiators. USE CLEAN WATER
WHEN SERVICING ALUMINUM RADIATORS.
• Do not open the hood if you can see or hear steam or
coolant escaping from the engine compartment.
• Do not remove the radiator cap if the radiator feels
warm.
• Do not remove the radiator cap or coolant recovery
tank cap if the coolant in the recovery tank looks like it
is boiling.
• Wear eye protection.
• Wear gloves to protect your hands against excessive
heat or the effects of chemicals on your skin.
• Prevent dirt and water from entering the transmission
oil cooler.
NOTICE: Never use shop air to pressure test
radiators that is not regulated at 138 kPa (20
psi). Pressures over 138 kPa (20 psi) will dam­
age the radiator.
REPAIRABLE LEAKS
There are two types of leaks that can be repaired on the
aluminum/plastic radiator: core leaks and gasket leaks (fig­
ure 23). Leaks in the plastic tanks cannot be repaired.
Core leaks can occur in a tube or in the joints between
the tubes and headers. Gasket leaks can occur in the joints
between the plastic tanks and the headers, or in the joints
between the oil cooler fittings and the tank. Some leaks can
be repaired while the radiator is on the vehicle; however, it
is usually best to remove the radiator.
113 121
113. Tank Gasket
116. Oil Cooler Gaskets
118. Drain Cock Gasket
121. Core Tubes
123. Joint Betweeen Tube And Header
Figure 23 — Possible Leak Areas
Repair Methods
There are several methods that can be used to repair the
radiator core, but the hot-melt adhesive method is the most
effective.
113
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