Puking coolant

[Waterloo]

Head gasket or bad head. How many miles on the truck, and does it still have the mandate? That is what mine did when the head went. At the end, it actually blew my radiator into pieces, it was building that much pressure in the system. Took her in and did a total in frame. If it is a bad head, do not reman it and do not put a Cummins reman head on either! Only NEW OEM, these heads are one time use only.

Tell your buddy to call the local auto parts store and ask for a block test kit. Napa stocks them. If you have exhaust gas in the system you will know in a matter of seconds.

Also, rare, but happens, the air compressor can cause the same symptoms. I forget how to test for this in regards to pulling the lines. What I did is drain the air tanks, left the tank valves open and fired up the truck. It was the head.