Inspection: Core Groove Where Tank Is To Be Mounted; Repairing Core - Mitsubishi 6M60-TL Service Manual

Inspection: Core groove where tank is to be mounted

• Check the groove on the core where the tank is to be mounted
for adhesion of foreign substances or cracks.
• If foreign substances are found, rub the area with #1000 sand-
paper or a like gently so as to avoid scratching the surface, or
use compressed air to remove them.
• If there are cracks in the groove, repair or replace.
CAUTION
• If the packing and tank are installed onto the core without
removing foreign substances from the groove, coolant leak-
age will result. Be sure to inspect and clean the tank mount-
ing groove along the entire periphery (even a hair can cause
leakage).

Repairing core

CAUTION
• The core is repaired by means of tungsten inert-gas arc
welding (TIG welding), which should only be performed by a
skilled welder.
• It is extremely dangerous to weld on a wet core. Before
welding, ensure that the core is completely dry.
• Using a stainless wire brush, brush both ends A of the leaky
tube and the areas B around the tube ends until the base alumi-
num is exposed.
• Before closing the tube at both ends by welding, drill a small
breather hole in the tube.
CAUTION
• If a breather hole is not provided, the tube may develop
small pinholes due to escaping air.
• Ground the core at the support.
CAUTION
• If welding is performed without the core properly grounded,
this can lead to short-circuit where the base metal may
melt.
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