these connections to prevent engine vibrations from
being transferred to the radiator.
When performing prestart checks on the radiator
system, check for leaks, particularly where the tanks are
soldered to the core, because vibration and pulsation
from pressure can cause fatigue of soldered joints or
seams. Bent fins should be straightened and the radiator
core checked for any obstructions, tending to restrict the
air flow. Radiator air passages can be cleaned by
blowing them out with an air hose in the direction
opposite to the ordinary flow of air. Water can also be
used to soften obstructions before applying the air blast.
In any event, the cleaning gets rid of dirt, bugs, leaves,
straw, and other debris that would otherwise clog the
radiator and reduce its cooling efficiency.
Spraying high-pressure water to soften an
obstruction on the radiator can cause damage to
the fins and core.
All hoses and tubing should be checked for leakage
and general condition. The leakage may often be
corrected by tightening or replacing the hose clamps.
Figure 1-44.Liquid-cooling system.
Deteriorated hoses should be replaced to preclude future
troubles; for example, hoses sometimes rot on the
inside, allowing tiny fragments to flow through the
system and become lodged in the radiator, tending to
clog it and cause overheating. For this reason, all old,
cracked, or spongy hose should be replaced as soon as
the condition is discovered during the prestart checks.
RADIATOR PRESSURE CAP. The radiator
pressure cap (fig. 1-45) is used on nearly all modern
Figure 1-45.Radiator pressure cap.
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