Coolant Change and Heat Exchanger

[wayneking]

I want to change the coolant in my Beta Marine 35. While I'm doing that I also want to clean the heat exchanger tube stack. I've never done this before so I have a couple of questions. Is it a good idea to run fresh (distilled) water through the engine before or after the cleaning or is cleaning the tube stack sufficient? The current coolant looks a little brownish so I'm wondering about what cleaning procedures I should be doing. Also, what about the water heater? Looks like the engine coolant runs through it to provide hot tap water, correct? So anything I should pay attention to on the heater part of the system? It doesn't seem like whatever coolant is in the heater will drain very well by just draining coolant from the engine so maybe another reason for a fresh water flush? Do most folks do this themselves or have a pro with the right equipment do it? I'm just not sure how big of a job I'm taking on. Thanks.

 

[Prairie Schooner]

Hi Wayne,

This is something I need to do in the next weeks. Below are some links I've socked away which were helpful. Most seem to rely on circulating the rinse with the engine running. I'm going to try to use a submersible pump instead because the coolant system is all in parts.

- https://www.cruisersforum.com/forum...freeze-part-of-the-cooling-system-209163.html
- http://sail-delmarva.blogspot.com/2009/11/marine-winterizing-antifreeze-and.html
- https://www.c34.org/wiki/index.php?...Mainesail_aka_Rod_Collins_aka_Compass_Marine)
- http://realitycheck.me/draining-the-coolant-from-the-universal-m25.htm
- https://www.catalina36.org/forum/technical-discussion/best-procedure-coolant-flush-and-replace
- https://www.catalina36.org/forum/technical-discussion/best-procedure-coolant-flush-and-replace

Sorry, all I can do is throw links at you. No experience yet to share. My journey with this is in a thread called Coolant Conundrum.

Good luck,
Jeff

 

[JSM]

I changed coolant and cleaned the heat exchanger on our Universal M2xp a few years ago. We are in fresh water so there was only a small amount of mineral buildup in the tubes. I removed the heat exchanger from the engine and took the ends off. An overnight soak in CLR (calcium , lime rust remover) did the trick. No need to flush with distilled water. Put everything back together and fill with fresh coolant.

 

[wayneking]

Hi Wayne,

This is something I need to do in the next weeks. Below are some links I've socked away which were helpful. Most seem to rely on circulating the rinse with the engine running. I'm going to try to use a submersible pump instead because the coolant system is all in parts.

- https://www.cruisersforum.com/forum...freeze-part-of-the-cooling-system-209163.html
- http://sail-delmarva.blogspot.com/2009/11/marine-winterizing-antifreeze-and.html
- https://www.c34.org/wiki/index.php?title=ONE_PROCEDURE_TO_FLUSH_the_ENGINE_CLOSED_COOLANT_SYSTEM_-_from_RC's_(aka_Mainesail_aka_Rod_Collins_aka_Compass_Marine)
- http://realitycheck.me/draining-the-coolant-from-the-universal-m25.htm
- https://www.catalina36.org/forum/technical-discussion/best-procedure-coolant-flush-and-replace
- https://www.catalina36.org/forum/technical-discussion/best-procedure-coolant-flush-and-replace

Sorry, all I can do is throw links at you. No experience yet to share. My journey with this is in a thread called Coolant Conundrum.

Good luck,
Jeff

Hi Jeff,

That's a lot of info! Thanks!! I'll let you know how this goes. Good luck with yours.

Wayne

 

[Pete the Cat]

I didn't read all the instructions that Prairie Schooner posted, but I would suggest that anyone who owns a "marinized" tractor engine like Universal, Westerbeke or Beta should take the system apart (that means get the heat exchanger out of the boat and the end caps off and visually inspect the elbow) after 1000 hours and see how bad it is. Then set up a schedule based on what you see. I know a lot of folks use cleaning fluid flushes, but I think there is no substitute for taking a view yourself inside the whole system. If the heat exchanger is really crudded up you will need a radiator shop who can clean and pressure test it. My slip neighbor just had his out and the shop found a pinhole with 1000 hours on it--I suppose if you are not losing or gaining coolant, you can skip that. Inspect the elbow and determine the next inspections. I just would not rely entirely on exhaust water flow for thinking everything is OK. This is the kind of maintenance that a lot of folks put off because it is messy and a PIA. But waiting for failure could ruin a trip. A 5/16" power driven socket is really nice for removing hose clamps.

 

[sailing42]

I have a Yanmar 2GM diesel and I removed the heat exchanger and cleaned out the tubes with a small round brass brush + rod I got at a outdoor store - I believe it was for a .22 caliber rifle. Fitted perfectly in the small tubes and cleaned them out like new. I originally tried soaking it in CLR but that didn't seem to work.