Join Date: Oct 2009
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Heat Exchanger Zinc Issues/Questions
I have tried to replace the heat exchanger zinc for the first time in my new-to-me Catalina 28 with a Universal M25-XP, and have encountered something which I didn't quite expect. I expected water to come out when removing the zinc drain plug, but when the zinc was removed, engine coolant came out. Is this normal? Should I have expected this? If so, would it stop once the amount in the heat exchanger emptied, or would it keep emptying until all coolant (not just that within the heat exchanger) emptied?
Also, the zinc I had (7/16 wrench) would not fit. The wrench size was correct, it appeared that it was too long. This one was 2 inches I believe. Barely any of it would fit, and I ended up putting the old brass plug back in...which is zinc-less. Is there something obstructing this zinc, such as old, broken off zincs, or is this zinc to long and needs to be cut. If needs to be cut, does anyone know the correct length? Or do I just cut it until it fits...
Lastly, if there is an obstruction blocking the new zinc (i.e. broken off zinc)...should I remove the endplates? I know new seals would be needed, but what else would need to be done? Would I only need to empty the heat exchanger of all liquid (this kinda ties into the first question above about engine coolant).
I don't know why something seemingly so simple has become so difficult...but between getting the wrong zinc sizes, and now this...replacing this zinc has become my nemesis...and I can only imagine what awaits later...