How much coolant in a big Cummins?

[Chris142]

I bought an old Peterbilt. It has an 855 cu in Cummins inline-6 diesel engine.

The stuff in it now is very murky so I'm going to flush it out with a hose, then use Deionized water to flush out the tap water.

How much coolant to add? Whats the system capacity? I also have some of that Nalcool stuff that helps prevent pitting of the liners.

How much of that to add?

 

[ChrisW]

Probabaly in the several gallons variety. Those rigs don't mess around. I would maybe measure what comes out?

 

[Buford T. Justice]

Perhaps you could call a Peterbilt garage and find out.

 

[Chris142]

Nobody is open on Sundays here. I'm mainly concerned with it freezing and cracking the block. It got down to 25F last night! I have 4 gallons of green antifreeze. I think that should be enough to prevent it from freezing.

 

[pmwalter]

To give you an idea, my 7.3L 8cyl Diesel takes eight gallons. With four of them antifreeze and four distilled water, you should be fine with what you have.

 

[Chris142]

I did a 1/2 flush with the garden hose and then dumped in some deionized water and let it run and drained that.

I added 4 gallons of coolant and the rest water. Mixture is only 33%. Good enough to stop it from freezing here but I need to drain it again as it's turned brown already.

 

[pmwalter]

Took me 9 (or 8, I forget) flushes to get all the old coolant out of my 7.3L navistar. Only then was I convinced that most to all of the old fluid was gone. I know it's kind of over kill to flush that many times, but I was just trying to show my doctor that I wasn't obsessive compulsive.