Re: [Amel Yacht Owners] Heat Exchanger

John Clark

Hi Pat,
    I attached the TAMD22 service manual, the cooling system starts on page 93.  I can tell you if you are blocking holes it will significantly reduce the heat removal ability of the HX.  I see in the manual that there appears to be o rings on the metal end caps.  This is how I would expect it to be.  

What kind of over heating issue do you experience?  It could be something unrelated to the HX like drawing air from a cracked SW hose(happened to me) or leaking anti siphon, leaking backflow preventer....

                                          Regards,  John

John Clark
SV Annie SM 37 

---In amelyachtowners@..., <sailw32@...> wrote :

Mark, Reading your reply, I realized that I left out an important fact ,that my engine is a Volvo TMD22a . So my exchanger may be different from yours. I suspect it is, I see no where ,where a O ring would reside.All my small tubes were clear , what was partially block were two of the four larger holes in the bronze housing where antifreeze passes through.On my H/E there is two rubber boots on either end where the water enters and leaves from and they are secured with s.s.clamps. If they should leak ,and they are under pressure raw water could mix with the antifreeze.So if anyone with a TMD22a could tell me if there is Orings or silicone ,I would appreciate it.

-----Original Message-----
From: 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...>
To: amelyachtowners <amelyachtowners@...>
Sent: Fri, Jun 1, 2018 5:13 pm
Subject: RE: [Amel Yacht Owners] Heat Exchanger

Hi Pat,
It sounds as though you are on the right track.
The ends should be sealed with a rubber o-ring. Depending on the engine type there are sometimes 2 o-rings. There should not be silicone. You should be able to look through the tubes and see nothing but air. Any obstruction is going to cause you grief especially near the ends as this is where the sea-water changes direction. If you look at the design of the HE, you will see the how the seawater changes direction two times before moving on.
While you are in there, also check the after-cooler, if you have a turbo charger. This can be another are where the copper tubes become blocked and foul the flow of sea-water.
The anti freeze is moved along the outside of the tubes by the engine’s fresh water pump. The sea water is moved by the sea-water pump impeller on the inside of the tubes. The anti-freeze is cooled as it makes contact with the other side of the copper tube.
Hope this helps you.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Friday, June 1, 2018 1:23 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Heat Exchanger
I have had my heat exchanger off several times over the years ,and reinstalled it as the previous owner had and not questioned it ,until now. I have had an overheating issue for years and am resolved to solve it . The previous owner applied silicone on the end caps to seal them. Is this normally done? When I just removed the H/E I found that as I pushed the cap on the last time ,the silicone was pushed back and covered better than 50% of one of the four holes and about 25%of another. Which brings me to another question. Is the antifreeze forced through the holes or does it just come into contact with the tubes as it moves along with the flow,I assume the later.
SM Shenanigans #123

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