C 15 loosing coolant

You must be burning it, I would guess.

 

Check the bottom of your fuel tanks.

 

Is this one of my SDP relatives ......?

 

Put a clear bottle on the overflow tube and run it. See if its pushing it out there.

 

If your engine is 07- '09 you may want to check deep behind the turbos. There is a tube that comes from the coolant box, and right after it dissapears behind the turbos it connects into a " 2" long hose" the clamps give out after so many hours and then it leaks coolant. The engine gets so hot on that side that you will never see a #### drop, it all will evaporate.
On my engine it drips a tiny bit when I start the engine and when the engine is cold Which Iis the only time this is visible. The tube replacement part costs about $240.00 and the hose is $5. The fun part is taking off all of the piping to get to the #### hose. You'll need a flashlight and to stick your head under the turbos to see it. GL.

 

Hi, there bad for head cracking and coolant ends up in cylinders. thats really the only place it can go if you cant find it.

Grant

 

Use a clear bottle with water in it ,make sure the end of the overflow hose stays in the water, let truck reach operating temp and watch for bubbles. If bubbles appear diagnose radiator cap,air compressor, headgasket/cracked head or cavitated liner.
good advise from Lucar on `07-`09 engine.