Bad Heat Exchanger???
- Thread starter MichaelNJ
- Start date
It's been very common to "turn back" a tube or two in a car radiator instead of re-core it or do a complete replacement. So say your HX has 30 tubes. If one leaks, you're probably OK with 29 if you block the leaker off. That's Charlie's suggestion. Counterpoint of course is "If one tube leaks, how long before the next?" It's easy for a qualified, equipped person to take the "tanks" off a car radiator to work on the core. Your point is that you aren't sure this idea works with HX, and I don't know one way or another. But HX has end caps that makes blocking a leaky tube work about the same way as with car radiator.
Agreed. That's why I'm waiting for my mechanic to look at it and give me his opinion. From what I understand, the lifespan of these things is 8-10 years and that's where I'm at. SO I'll probably just replace both of them and be done with it.
Sorry, my only computer died last week and I was on a timed library computer about to time out in about 1 minute & apparently hadn't read the post of no pencil anodes in that H. Exchgr. Which is really hard to imagine ( though my Crusader oil and ATF cooler has no anode either.) I've never seen a main H.Exchr w/o a pencil anode.
I've been waiting for sandy to explain the full repair procedure since I've gotten tired of repeating over and over, both the repair, short cuts and work arounds of the different systems on small/mid size boats.
So, remove both end caps. plug either the inlet or outlet of the coolant section of the H/E and have it filled. Keep fill/radiator cap tightened. You only need about 10 PSI so be careful as most compressors have at least a 70PSI working pressure. Look thru the tubes as that's where the raw water flows thru. A leak will show up almost immediately. Finding it is a little more difficult if you don't have a bath to put it in.
After locating the leaking tube, you have to decide if you want to just plug both ends with JB weld or plug the tube with 1/4" brass rod. Available in hardware stores or welding supply. clean both inner ends of the tube with a .22 wire brush or .223 chamber brush. Both cleaning procedures are for soldering OR JB weld. Cut brass rod 1/4"-1/2" short so there's 1/8"+ shy on both ends to make it easier to solder or fill with JB....Oh Yeah, use acid core solder if you can't clean or aquaflux if it is.
So, remove both end caps. plug either the inlet or outlet of the coolant section of the H/E and have it filled. Keep fill/radiator cap tightened. You only need about 10 PSI so be careful as most compressors have at least a 70PSI working pressure. Look thru the tubes as that's where the raw water flows thru. A leak will show up almost immediately. Finding it is a little more difficult if you don't have a bath to put it in.
After locating the leaking tube, you have to decide if you want to just plug both ends with JB weld or plug the tube with 1/4" brass rod. Available in hardware stores or welding supply. clean both inner ends of the tube with a .22 wire brush or .223 chamber brush. Both cleaning procedures are for soldering OR JB weld. Cut brass rod 1/4"-1/2" short so there's 1/8"+ shy on both ends to make it easier to solder or fill with JB....Oh Yeah, use acid core solder if you can't clean or aquaflux if it is.
Thanks Charlie. My Mechanic did the pressure test. I think he used a hand pump and a bucket of soapy water. Only one tube is leaking but he said it was a pretty big hole but you can't see it. It's one of the tubes on the outer part of the circle. He didn't think solder was a good idea because it will heat other joints that were close by and may cause a new problem. He did not believe that the problem was caused by corrosion so he felt that it is worth trying to repair. His original idea was to use an epoxy in a syringe and fill the tube. I don't think that would work because the epoxy will leak out the hole into the fresh water side. He wasn't crazy about introducing a new kind of metal by inserting a rod. I'm thinking the JB Weld 2 part epoxy putty. Trying to push it into the tube as much as possible.
All you have to do is plug both ends which prevents raw water from entering that tube. It's not necessary to fill the whole tube with epoxy. As far as soldering, the H/E is all made of some type of copper alloy...the same as a brazing rod or any brass rod. Actually, most brass is most likely a bronze alloy instead of the copper/zinc of brass.
Fixing a H/E is a very simple procedure
Most of my answers are more involved than any specific question or problem. GVP almost always answered questions and addressed problems in the same manner. Not trying to compare myself to George but It doesn't take very long to understand that many people may have the same problem and need information whether to fix it themselves or take it to a mechanic. At last count, there was 513 views of interest to your post so you are helping quite a few boaters.
Fixing a H/E is a very simple procedure
Most of my answers are more involved than any specific question or problem. GVP almost always answered questions and addressed problems in the same manner. Not trying to compare myself to George but It doesn't take very long to understand that many people may have the same problem and need information whether to fix it themselves or take it to a mechanic. At last count, there was 513 views of interest to your post so you are helping quite a few boaters.
I think I would fill the tube as much as possible with something incompressible. Changes in altitude, barometric pressure, and temperature will be working to loosen that epoxy at the tube ends. A plastic rod would alleviate any concern regarding dissimilar metal.