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U Cooler leaking from Zinc

R

ralphs

New member
I have been reading the forum for a few weeks and really appreciate all the good advice. I have a 1985 Californian with twin 454 Crusaders (model 350). Fresh water cooled with around 650 hours. The starboard side runs 15-20 degrees hotter at cruise (190-200 on dash gauges, vs 160-170 for port). I just bought an IR thermometer to check the temps more accurately next time I go out. I get some steam out the exhaust, but it seems about the same on both sides. I will also check the impeller before I go out again.

I suspect the U cooler based on forum advice. I unscrewed the zinc and only 1/4 inch came out. Rest is still stuck in the hole (probe hits metal immediately). I put the cap back on and it would not tighten much (threads are mangled). It now leaks continuously (about 1 drop per second). Should I buy a new cooler or try to repair this one? Curiously, the port looks newer (flat bottom design with horizontal zinc). The port side has a 45 degree twist at the exit elbow, which makes it hard to route the hose back to the heat exchanger. Should I go with the older stlye (90 degree twist, straight route to HX), or newer one? I don't understand why it was replaced with poor fitting newer style, unless there is some advantage.

Thanks in advance!
 
There have been a few different vendors making these over the years, with a few minor design mods. THe flat, cast bottom is the older, traditional style. You can still buy these with the 90 degree exit, instead of the 45 deg mount. I've found one vendor with that style. If your leaky cooler is over 10 years old, i'd replace it. If not, then remove the bottom assembly with MAPP gas torch and inspect and clean up the internals. You can drill and retap the zinc pipe fitting easily.
 
Concur w/ DD on the > 10 yr, replace approach.

On the newer unit with the "45 deg" outlet; it is very easy to sweat the joint and rotate the outlet to be oriented where you want it to be.

On the zinc plug, if the threads on the housing are mangled, and you determine that fixing it is viable, it is unlikely you can recover the 1/4" NPT threads. I'd drill them and retap for 3/8" NPT and then locktite a 3/8" NPT to 1/4" NPT reducer in. that way you can keep interchangability with the zinc plugs.
 
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