Peterbilt 579 MX13 blowing coolant out reservoir overflow

Could be, but being foamy leads me to think it’s a failing/cracked head gasket.

How many miles?

 

1.Does it regen good
2.coolant is still the original red color? because that will eliminate the egr cooler (inspect rear cooler pipe if unsure, should be sooty DRY)
3An air compressor head kit is not cheap but a common failure point (smoke white a little bit under load)

my KW(though it has a cummins) had a cracked head, ran fine, but it went to pushing out coolant and looking foamy and had a ton of pressure.
Wouldn’t do it at idle regardless of how high you revved it.
But take off even with empty trailer and it’d do it. low coolant light, blowing out the coolant.

 

MX 13 pushing coolant



This guy shows trouble shooting on compressor about 4 minutes in.