Jake1982

Thanks. There is a new surge tank on there and when we did the gasket we sent head in to be cleaned and tested. I am starting to think Mack may of screwed up when they put the cups in.....looks to be a bit of carbon in the new tank...

I have a 2011 Mack that pressurizes the cooling system to the point that the coolant blows out of the overflow. This only happens when the truck works. It can idle for hours or pull an empty trailer down the highway with no issues but once there it has a load on it pukes out the antifreeze within 10 miles. I have changed the compressor. When that didn't work I had the waterpump and waterpump housing changed. I have also done a head gasket, new cups and new egr cooler. I am out of ideas....any help would be appreciated.