METAL BODY REPAIR - OD1653 - LESSON 2/TASK 2
(b) Reverse flushing is similar, except that the lead away hose is
attached to the inlet connection and the flushing gun to the outlet. Both
methods of pressure flushing are effective when the radiator is not too
(3) Boiling Out Radiators. Sediment so firmly packed in the radiator
chemical solution. The vat is made so that the radiator may be lowered
beneath the surface on a level controlled rack. After the radiator has
boiled for a sufficient amount of time, it is removed from the vat and
placed in a spray booth. In the spray booth the outside of the radiator is
washed with air pressure and water to force out dirt, bugs, lint, and other
material lodged between the fins, so that free circulation of air around all
parts of each tube and fin is restored. Also, the interior of the radiator
is back flushed with air pressure and water.
(4) Cleaning Solution. To make a good cleaning solution, dissolve one
pound of ordinary baking soda in one gallon of water. If a commercially
prepared chemical cleaner for radiators is used, follow the direction on the
(5) Rod Cleaning. If flushing or boiling is inadequate, scrape the
inside of the water passages with a bristle brush or cleaning rod. For
tubular radiators, this may be merely a round wire with its end rounded to
avoid puncturing the tube. For honey comb or cellular radiators, use a flat
strip of metal with edges and ends rounded, not quite as wide as the water
passage, pushing it back and forth through the water passages.
c. Testing Radiator for Leaks. Before testing a radiator to locate
leakage, inspect it carefully for visible leaks and solder them promptly, so
that the test will be sensitive enough to reveal less obvious defects.
There are two standard methods of testing: one by introducing air (under
light pressure) into the radiator, immersing it in water, and locating the
leaks by the appearance of bubbles; and the other, by filling the radiator
with water and locating the leaks by the moisture seeping through. Either
test is satisfactory, although the air test method is preferred. Mark the
leaks as soon as found to facilitate locating them during repairs.