compressed air going in my radiator (250 Cummins)

[tkcrane89]

I have compressed air going into my radiator. (250 Cummins) Does anyone know what my problem could be & what do I need to do? Thanks
Its a 5 ton military truck. I unhooked my airline off my air compressor & it stops.

 

[Glenngineer]

Sounds like a head gasket.

 

[tkcrane89]

i just rebuilt engine . when i take my air line off my air compressor it stops

 

[Glenngineer]

i just rebuilt engine . when i take my air line off my air compressor it stops

That's an odd one ,hopefully one of the more knowledgeable members chime in.

 

[98G]

Sounds like a head gasket.

My first thought also, but that wouldn't stop when the compressor is disconnected.

 

[doghead]

Water cooled air compressor.

Most likely a cracked compressor head or bad compressor head gasket.

 

[Swamp Donkey]

What model 5 ton exactly? Compressor could be leaking internally, or if it's an M939, the shutterstat could also be leaking around the thermal probe.