12.7 Detroit pushing coolant out of overflow

Some of the last 12.7 Detroit's have stainless steel cups, screw in type like the 14 liter, very easy to replace with the special tool.

 

The main thing is to keep the dca levels correct.The test strips are cheap but have a short shelf life no need to buy a big pack. Should be part of PM at truckstop.Also use only heavy duty truck antifreeze.I always used regular mixed with distilled water and flushed it annually. Had good luck on first truck. However I’ve been told that There’s a big difference and recently switched to red final charge. It’s cheap at Tractor supply comes pre mixed and you’re supposed use a filter with it that automatically adds dca as needed.Supposedly it has special additives to reduce foaming and tiny air pockets which causes cavitation which causes pitting.I think I may have caused a cylinder to drop at 825k on my last truck by using regular antifreeze. It makes sense. Time will tell so far so good

 

I wonder if I can upgrade to that style head when I overhaul mine it has a build date of Nov 98.

 

Probably, if you put the newer cylinder head. Get your block serial number and go to Detroit Diesel and ask them.

 

Ok so I got the truck to a shop and they first diagnosed it as water pump and thermostats, got those in and it seemed to do better but still not quite right. Threw a new radiator in and all seems to be good now. I found the steepest hill I could and gave it hell up it and it barely hit 193. Empty trailer though. Will know more when I get a heavy load and hit some hills. But all seems well now.

Edit: I also replaced the cap for the hell of it, but it seems to me that it is just a simple plastic cap with no venting or anything going on. Should I have replaced the other cap(overflow side)?

 

Im jealous need that radiator done myself. Only a problem on a hill loaded heavy if it’s over 70 degrees outside. Been doing mine for 3 yrs now!! Soon be cold gonna do in next spring unless I get an overhaul first!

 

@Terry270

I replaced the whole reservoir (from Amazon less than $100). Search under Dorman parts. It comes with brand new caps & coolant sensor.

Old plastic develops hairline cracks. Swap it out, and be done.

 

I was going to order one from Volvo but it was a few days out and the cap was in stock. I'm like you I'd rather have new especially since I have basically a full new cooling system now.

 

Just buy it online. Much, much cheaper. Trust Me.

 

As good or better than OEM?