If the temperature differential is greater than the speci-
fications, check the CAC for dirt and debris on the fins
and clean as necessary. If the problem still exists, check
the CAC for debris in fins or between the CAC and ra-
diator. Confirm full fan engagement.
Checking - Air Leak
To check the CAC for cracked tubes or header, remove
the inlet and outlet hoses from the cooler. The CAC does
not have to be removed from the chassis.
Install a plug or cap on the outlet side of the cooler. Install
a pressure gauge, air supply line, and air pressure reg-
ulator to the inlet side of the cooler.
To prevent possible injury, secure safety chains on the
test plugs to any convenient capscrew on the radiator
assembly. This test must not be performed without safety
chains securely fastened to capture test plugs in the
event of a blow-off.
Apply 207 kPa [30 psi] of air pressure to the cooler. Close
the air pressure regulator.
Monitor the pressure gauge and determine the rate of
pressure decay with a stop watch.
If the pressure decay is 49 kPa [7 psi] or less in 15
seconds, the cooler is okay. If the pressure drop is greater
than 49 kPa [7 psi] in 15 seconds, check all connections
again.
Determine if pressure decay is caused by a leak in the
CAC or from a leaky connection. Use a spray bottle filled
with soapy water applied to all hose connections, and
watch for bubbles to appear at the location of the leak.
Charge Air Cooler (3-11) Section 3 - Combustion Air System
N14Page 3-30
To Next Page
Loading...
