Universal M25 Coolant Issue

[CruiserDave]

My wife and I are on our way down to the Bahamas and have run into a problem. Yes I check my fluids every other day. Today was oil change day. Old oil was fine. Then I checked the radiator (fresh water cooling) and found the coolant was clear and tasted slightly salty. I always keep a 50/50 anti-freeze mix. Could this be a problem with my heat exchanger? I am good with tools (basically rebuilt boat), what is involved with replacing the heat exchanger? Thanks for any help/advise.

David

 

[Witzend]

Now this is just a theory mine you, the (2) systems run at different pressures, correct. The closed system (the one with antifreeze) builds up to what, about 10PSI when it's hot. The fresh water system should be running much less, unless there is a restriction, then it might get up the 2-5 PSI I'm guessing. So when the system gets hot, antifreeze will pass through any breach in the exchanger, untill the pressure is equalized. Once it cools down again it may suck fresh/salt water back into the system, or maybe just the pressure developed from being below the water line is enough to force water back. After enough cycles it would dilute the antifreeze. Unless you have mixed up some pluming,
I'm guessing your on the right track.

 

[Stu Jackson]

Dave, Google for a Universal dealer wherever you are, or contact Sendure see http://c34.org/bbs/index.php/topic,3744.0.html. Sure sounds like a HX issue. Where else would coolant and raw water mix, unless there's something more going on inside the beast.

Replacing the HX is kid's work. You most likely have two big hose clamps holding it on, plus the four hoses. If you get the bigger 3 inch HX you'll have to bend the bracket down to have it pass the exhaust riser at the aft port end, so it may be worth your while to replace the old 2 inch with a new 2 incher, unless you'd already installed the 3 incher.

There was a recent discussion about HXs right here. Check some of my previous posts.

Good luck, let me know if there's anything else you need.

 

[CruiserDave]

Thanks

Thanks to both of you! You've both confirmed my suspicions. An overnight delivery and we should be on our way again. Nice place to "break down" in though.

David