METAL BODY REPAIR - OD1653 - LESSON 2/TASK 2
supplements it when the air test is suspected of being inadequate. Sediment
and lime deposited about leaky joints may be forced into the joints by air
pressure when the radiator is air tested, sealing the leak. A leak at the
joint of tubes and header plates often refuses to show up under air
pressure. For this reason, dry the radiator after repairing the leaks found
by air pressure, and test by the water method. With the radiator thoroughly
dry, remove the plug from the filler neck and fill the radiator with water,
being careful not to run it over or spill on the outside. Examine the core
carefully for leaks. Place the air hose over the lower end of the overflow
tube and hold the palm of the hand over the filler neck, while five pounds
of pressure is applied against the water.
(7) Marking Leaks. Adopt a uniform system of marking leaks. For tank
leaks, a sharp pointed tool is most adaptable. For honeycomb cores, bend a
strip of tin or small wire in the shape of a clothespin and insert it, bent
end first, at the leak. Let one end of the "clothespin" project farther
than the other to indicate which side of the cell is leaking.
d. Radiator Disassembly. When work is being performed on vehicle radiators
using the oxyacetylene welding torch as a source of heat, the flame is
always adjusted to a carburizing flame.
(1) Side Member Removal. Light and adjust torch to a carburizing flame.
Apply heat to the top radiator tank where the side members are joined by
solder (one side at a time). When the solder melts, move the top of the
side member away from the upper tank until the metal cools, then heat the
bottom part of the side member and remove it from the radiator.
(2) Overflow Pipe. Melt any solder tacks which might be holding the
overflow pipe to the upper tank. Beat the overflow pipe at the place where
it enters the filler neck and remove it from the radiator.
(3) Upper Tank Removal.
(a) Tapping. Using the oxyacetylene welding torch, direct the flame
to a point where the upper tank and header plate join. When the solder
starts to melt, tapping is commenced, moving all the way
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