coolant loss out of overflow hose!

I had the same problem with a bridge motor. No luck with a new radiator cap on mine turned out to be a cracked head.

 

I had the same prob years ago it was a head gasket. at least it did not let the water go into the oil & I was able to keep going, just having to keep putting water in every 400 miles or so, until I figured out what was happening.

 

Oh OUCH! That was not good news.

 

I feel your pain. Good luck

 

need to call a pete dealer and see what psi cap you need on your truck, if its still doing it then you need to connect a cooling system pressur tester and run the engine, watch the gauge and see what it does, you will get a little bit a pressure, but if the air compressor if pushing air into your cooling system or if your getting compression then you should notice it on the gauge, will be like a pulsing on the needle, if you have any doubt then take it to someone who knows what they are doing and pay the hour or two labor to have it checked out, better safe then sorry.

 

I know its not a CAT but I replaced the head gasket on my N14 only to have the same results 30k later. I was told to measure the liner protrusion. Got shims from Cummins and a new gasket. Haven't had her out yet to find out if it fixed it. Mine had oil in the coolant.