Hello, I have twin diesel's in my 530 Voyager that are 17 years old with only 950 hours on them. They run great, but I've recently noticed seawater dripping at the end cap of the port heat exchanger (1 drop every 5 to 10 seconds). My mechanic is recommending I replace both heat exchangers as well as service the aftercoolers and transmission coolers. My question is, does anyone have experience/comments on this? Can the leak be patched with JB Weld? What are the ramifications of letting it go for awhile. Heat exchangers, aftercoolers and transmissions were serviced 5 years ago (approx. 300 hrs ago). Thank you in advance for help/advice. Bob