2015 Peterbilt with Paccar MX 13 losing coolant

Thanks. I have my 2022 579, the same issue, consume coolant but never fond any leak point.
by the way, my mx13 eat engine oil as well, like 1-1.5 qt per every 6000 miles. if running mountains will be more......
any opinion welcome!

 

My 2015 T680 has Paccar MX13 drinks about a half gallon per day. And this after having the EGR and DPF cleaned.
No visible drips. Coolant loss is actually much worse than before servicing EGR, etc.

 

Get a clear water bottle fill half way.
Put the overflow hose in the bottle.
Start it up and give it a little throttle.
Hope there are not bubbles if there is are you got problems .
Good Luck