COOLING SYSTEM
TESTING AND ADJUSTING
Pressure Cap
2.
3.
4.
One cause for a pressure loss in the cooling system
can be a bad seal on the pressure cap of the system.
Inspect the pressure cap carefully. Look for damage
to the seal or the sealing surface. Any foreign mater-
ial or deposits on the cap, seal or sealing surface must
be removed.
To check the pressure cap for the pressure that
makes the pressure cap open, use the following
procedure:
1. Remove the pressure cap from the radiator.
Always stop the engine to inspect the cooling
system. Loosen the pressure cap to the first
stop and let the pressure out of the cooling
system, then remove the pressure cap. Hot
coolant and steam can cause personal injury.
Let coolant become cool before it is drained.
TM 5-3805-263-14&P-2
Put the pressure cap on the 9S8140 Cooling
System Pressurizing Pump Group.
Look at the gauge for the exact pressure that
makes the pressure cap open.
Make a comparison of the reading on the gauge
with the correct pressure at which the pressure
cap must open.
NOTE: The correct pressure that makes the pressure
cap open is on the pressure cap and is also in the
SPECIFICATIONS.
5. If the pressure cap is bad, install a new pressure
cap.
Testing Radiator and Cooling System for Leaks
To test the radiator and cooling system for leaks,
use the procedure that follows:
Always stop the engine to inspect the cooling
system. Loosen the pressure cap to the first
stop and let the pressure out of the cooling
system, then remove the pressure cap. Hot
coolant and steam can cause personal injury.
Let coolant become cool before it is drained.
1. Remove the pressure cap from the radiator.
2. Make sure the coolant is over the top of the
radiator core.
3. Put the 9S8140 Cooling System Pressurizing
Pump Group on the radiator.
4. Get the pressure reading on the gauge to 3 psi
(20 kPa) more than the pressure on the pressure
cap.
5. Check the radiator for outside leakage.
6. Check all connections and hoses of the cooling
system for outside leakage.
7. If you do not see any outside leakage and the
pressure reading on the gauge is still the same
after 5 minutes, the radiator and cooling system
does not have leakage. If the reading on the
gauge goes down and you do not see any outside
leakage, there is leakage on the inside of the
cooling system. Make repairs as necessary.
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