Loosing Coolant Part II

Have you tried a new coolant cap? Maybe the one on there is weak and letting some coolant seep through? Have you verified your temp guage with a heat gun to see if it is really running warm? I hope it is something simple and you can figure it out. Just my .02 cents. Good luck

 

My work truck 06 mack granite, is leaking coolant. For a while I couldn't figure out where it was leaking from. Slow leak. Never found any drips under the truck. Found it the head gasket is leaking in the rear against the fire wall.

Maybe check there? I have been running the truck for a few months like that. Yes my boss knows. None is going in the oil. Soon as our season slows down we'll get it fixed.

 

Try driving slower and keeping your boost down for the next 3000. If it quits or lessens it is likely the head gasket has a small leak under heavy boost. I have even seen one quit leaking after the driver did it, and no more coolant loss to this day. Either way, it is probably time for a head gasket and you might as well do an inframe at that mileage if your going to take the head off. You might consider having your radiator rotted first. It couldn't hurt and probably needs it at that mileage.

 

Do a oil sample to see if it's going there ... As far as running hot goes a lot of times just cleaning the fins on radiator and doing a flush will solve it if rads still in good shape.. Series 60s were bad for injector tubes leaking but a gallon every 3 k I'd think problem was elsewhere it would be smoking white if was burning that much and exhaust would drip sooty liquid .. If you have a tube on the overflow bottle you can try tying a empty plastic pop bottle to it to see if it's spitting outta there

 

If you're lucky it could be air compressor blowing pressure into the water. Disconnect the discharge line on the compressor while it's normal operating temp and see if you have any excessive pressure build up in radiator.
If you're not lucky it's a blown head gasket and with the miles it has that would probably be the issue.

 

Go to the diesel garage site and in the search section look for handy links, down a ways it has the complete bottle test, do the complete test, it will tell you what is wrong. I know as I wrote it, and it was looked over by others and they posted it.
Knowledge is king diagnosis by the ripping and tearing method as you have been doing acomplishes nothing but does add to the expense. What ever the problem is I guaranty you it will not get cheaper, and could get real expensive in a hurry.
Just a thought

 

when mine lost coolant out of over flow it was a bad head gasket/

 

EGR Cooler..