COOLING SYSTEM
TESTING AND ADJUSTING
TM 5-3805-263-14&P-2
Checking Radiator Air Flow
Tools Needed: 9S7373 Air Meter Group.
The 9S7373 Air Meter Group is used to check the
air flow through the radiator core. Overheating can
be caused by installing the wrong fan guard, low fan
speed, or a restriction in the radiator core (clogging).
The meter will give aid in finding a restriction in the
core.
When making the checks fasten the transmis-
sion in neutral, put the parking brakes on and
lower all equipment. Make all checks at engine
LOW IDLE and on the side of the radiator oppo-
rite the fan. Wear eye protection.
Take readings in a cross and diagonal pattern.
Make a comparison of the readings in each line the
same distance from the center of the fan. Permit
differences for restrictions such as guards, braces
and engine components which will cause a change in
the rate of air flow.
NOTE: All readings are taken at engine LOW
IDLE.
If the readings are not within the ranges, stop the
engine, put a strong light behind the core and inspect
for a restriction. If the restriction is from dirt remove
by steam cleaning. If the restriction IS from bent fins
use 2H1822 Radiator Fin Comb to make the fins
straight.
Checking Fan Speed
Tools Needed: 1P5500 Portable Phototach Group.
If the radiator core does not have a restriction,
check the fan speed with the 1P5500 Portable Photo-
tach Group.
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