60 series coolant pressure building, what is causing it?

Any air operated HVAC controls on the truck?

 

Guessing no fuel was mixing in oil or coolant?

 

I had 1999 S60 that was rebuilt at 1.1 million miles. They put a rebuilt head on as part of the job. After two week it was blowing coolant out the plastic holding tank. But only when pulling a big hill and engine would get up to 208+ F coolant. Took to another Detroit Diesel shop, they had put truck on Dyno and simulate pulling a hill. They found the rebuild head had a crack the only open when coolant was 208+F

 

The gasket was intact when you pulled the head? I can’t understand how you can tell it wasn’t leaking. Check the liner heights. I think it’s .01-.05 thousand, with no more than .02 between 2 adjacent cylinders. Get the head pressure checked. Might as well do an inframe now.

 

Check liner protrusion and have the head checked for cracks while its off.

 

I avoided them myself. Everyone has a different opinion. I used FP Diesel (Federal mogul). I’m happy with it. My first choice was Mahle, but they were behind on orders. They had just bought Clevite bearing, and re doing their part #s or something. Mahle makes the original pistons. Both are good kits. FP was a bit less. Also used a DD reman head through Freightliner Dealer. I was told to avoid aftermarket heads. Some have been found to be milled too much. Detroit kits don’t come with rod bearings. Aftermarket kits do. Bearings are another $350, plus core deposit. Detroit does research on old bearings and heads, so I’ve been told by an Engineer at Detroit.