Anti freeze leaks from Thru-hull strainer when on the hard for bottom painting.


New member
I could use some help on a problem that arose when we hauled Encore out to bottom paint. The hull was fouled, but no sign of blisters thankfully. However, just before we put Encore in the slings, the yardman asked me if I knew that antifreeze was dripping out of the port raw water engine intake. I looked, and sure enough, there was a steady drip, having filled up half of an empty paint can. We put Encore in the water, as we had to get it out of the yard, and I decided that we could motor home on one engine (which we did). Once home, I opened the thru-hull strainer and nice green anti-freeze began to flow out. Interestingly, with Encore in the water, there didn't appear to be any anti-freeze leaking from under the boat. (verified by diving under with a mask). So that's the set up.

Now I need some suggestions. Where besides the heat exchanger could the closed system cooling mix with the raw water? I'm at a loss, and could use some suggestions.
Jim Lanza
Punta Gorda, FL
I'd check the port heat exchanger...if its leaking, it should (have been) be low. if so, I'd pressure test it...if you don't have the tester, most any radiator shop should be able to test it...they should also be able to repair it if in otherwise decent condition...

I'd also be inclined to check the raw water pump...if its passing antifreeze when stationary, its likely in need of service, too...
Jim, agree with Makomark. Also if oil coolers have not been replaced in the last five years, nows time to do so. Admiralty copper coolers were supplied as standard on Lehmans. Expected life about 5 years and heat exchanger about ten. Cupro nickel is available which extends the life of the coolers and exchangers but variables such as sand in cooling water, zinc maintenance and stray electrolysis play a big part in life of coolers
Charlie W