My friend has 2002 Mack 300 the truck was idling and started smoking very minimal has never smoked before he got in the truck stepped on the accelerator pedal brought RPMS up motor sounded fine no issues the shut it off and notices antifreeze leaking out of the air dryer tries to start the truck up but it turns over then stops like it locked hydro lock. I don't think it is a head gasket because the truck ran fine until he shut it off no over heating or high temp oil is clean and not over full. I have never seen this happen before and have been around trucks over 40 years is it possible that the air compressor head gasket let go and is filling with fluid forcing it out the air dyer and also causing the motor to not turn over any and all help would be great. thanks in advance John
I think for sure you have a faulty compressor, that's pretty much the only thing that will dump coolant from the air dryer or an air tank. And though I've never seen it before, I suppose a serious failure of the compressor that's dumping substantial coolant into the compressor could backfill the air intake piping of the compressor which typically connects to the engine air intake piping thereby injecting coolant into the engine combustion chambers. Me thinks your friend needs to dig into that thing before he bends a connecting rod cranking the engine.
I would be disconnecting the intake to the compressor. Could be a leak in the aftercooler if equipped, or a cracked head or similar issue up top. Honestly... I doubt the compressor is the problem. But it does crop up occasionally.
Good point RZucker. :drinkup
That engine should have an air charge cooler. Three possibilities, head gasket which should pressurize the cooling system, liner issue, cracked head. Like RZ said pull the intake and discharge lines off the compressor, and take a look see. Truck Shop