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cbouch

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Apr 17, 2019
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I just replaced the o rings on the tube stack contained within the multi cooler. Previous to replacement I lost about 2.5 quarts of coolant on a 3 hour run. This engine has a reservoir recovery bottle and prior to o ring replacement nothing went into it. Now with the new o rings coolant does go to the recovery bottle when engine gets up to temp and retreats back into the engine when it cools. Does anyone else have a similar setup. The folks at tad tell me that my engine should have a one way cap not allowing the expelled coolant to return to the engine when cooled.I am very confused because they sold me the two way cap..I have also been told that I am not supposed to fill the multicooler with fluid and that it should be about on inch below the filler tube.. would love to compare notes with someone that has a similar engine setup. Also looking for a knowledgeable mechanic along the Erie Canal. Thanks
 
Do you have a multi cooler? Or a manicooler?

To my knowledge, it is true that the engines were not originally equipped with a vacuum-capable cap, just a pressure release. I don't think they operated at very high pressure, ~7lbs.

Personally, I don't see the harm in a recovery bottle. I've got them on my older 6.354(M).

If it seems to be going in and out, and when measured cold it is measuring the same every time, I'd be happy with it.

My memory is that those are filled to just below the filler cap neck. If you see the stuff underneath, it is too low. If it is up into the neck, it is too high. The real trick is to make sure there is no air in there, which requires filling slowly. I think there may even be a vent plug in the manicooler or multicooler or both, I don't remember.
 
I have the old style 1 way low pressure caps. Pushes a small amount into the catch tanks from heat expansion when I fill to top. No vents that I know of.
 
I have the multi cooler. It originally did not have an overflow bottle so I added one. It doesn’t go up and down with expansion, only up. Learned that the hard way. You need to remove the cap and visually check every morning. The pressure cap is 50 Kpa (7.2 Psig). The cap is physically larger than any car radiator cap so finding a pressure tester is difficult.
 
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