6v92 cooling flush

[Messi]

So I drained the coolant, to replace several hoses. It was pretty dark. Not the worst I've seen, but up there.

Can I flush this with some detergent, or am I better to just flush with water.

Thanks (again)

[Captain Ralph]

There is coolant flush products. I'm not an advocate of these on a 92 (or 53).
Please define what you meant "pretty dark".
Rust, sediment, change of color?

[Messi]

Blackish. This is the boat that was on the hard for about 5 years. Based on the hoses, and the chunks I found in the drain bucket, and smell, I’m thinking the hoses were disintegrating, and that is the cause.

[Captain Ralph]

The 92s use wet cylinder liners and are sealed in with O rings from the blocks coolant. It is because of these O rings that I am cautious of chemical cleaners.

If you are not in a hurry, I recommend flushing with water. running them a bit and flush with water again.

Use a pressure tester after last rinse. Do not ever pump up more that 7 PSI. Let that sit several hours to over night. You may loose a little but overnight 4 or 5 psi is good.

Then if all is good, charge it with Detroit PowerCool.


Your cap should also be 7 or 8 PSI cap.

[Messi]

Thanks Captain R.

it was the o-rings that had me ask the question, otherwise it would have gotten my secret cleaner.

I've plenty of time for mutiple water flushes. I plan to do the same for the starboard engine, but those hoses all looked ok for now