TM 5-2420-230-24-2
Cooling System - Air or Combustion Gas Test (008-019)
B3.9 and B5.9 Series Engines
Page 8-22
Section 8 - Cooling System - Group 08
Disconnect the coolant supply and the return tubes from
the air compressor. Use a short piece of hose to connect
the tubes together to prevent coolant loss during engine
operation.
Repeat the test for air in the cooling system as previously
described in Procedure 008-019. If no air is found in the
cooling system with the air compressor isolated, repair or
replace the air compressor. Refer to Procedure 012-014.
Combustion Gas Leak Test Kit, Part No. 3822985
Use combustion gas leak test kit, Part No. 3822985, or
equivalent, to test for combustion gases in the cooling
system.
It is recommended that the cooling system contain a mix-
ture of 50-percent antifreeze and 50-percent water during
the combustion gas leak test. The use of water only can
result in a color change in the test fluid from blue to tur-
quoise or light green during the test. This is not an indi-
cation of a combustion gas leak.
Drain the coolant level down approximately 50 mm [2 in]
below the radiator cap seal ledge in the radiator fill neck.
L-1078