alright so my dad took our truck to florida and was pulling a snowmobile trailer, he said that after he left it said that he was low on anti freeze, so for the whole trip he was putting anti freeze into the truck, he put about 1 1/2 gallons in it, the truck wasnt leaking or overfull it was loosing it somplace, so we brought it too our mech, and the engine code was throwing so they replaced the erg valve or whatever it is, they test drove it and it still was loosing some, their is a ton of pressure in the antifreeze surge tank, and the mech says its because we possibly blew a head gasket or did somthing in the motor, does anyone have any insight on to what could be going on? thanks