MX 13 pushing coolant

Dealer is likely correct, too much pressure is almost always a sign of a bad head gasket letting gasses into the system. It MIGHT be a bad thermostat or a bad waterpump. But the number 1 cause is the head gasket. And if the gasket is blown that means either a cooling problem and your truck overheats a lot and means something in the cooling system is borked. OR your compression timing is off. Id have your injectors and timing checked and have them check the thermostat and water pump. Also make sure the fan is correctly circulateing and you have no clogs in the coolant system.

Should prevent the problems going forward.

 

Air compressor head/gasket failure is common on EPA 17 engine as well. Make sure it was tested or bypassed before pulling the cylinder head.

 

Also I'd check EGR cooler before pulling head, but they rarely fail nowadays. Had a campaign to re-torque head bolts, was yours checked for campaign?

 

Best scenario. Glad to hear your up and running.