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Marelon Valve Replacement

PostPosted: Thu Sep 06, 2018 6:55 pm
by Camino
I have Forespar Marelon valves as thru-hulls on my F35 Pedrick. The po had cable tied all the thru-hulls in the open position. I removed all the cable ties except for the 3/4" water intake to the electric head. For some unknown reason I left that cable tie intact. Of curse I would work that valve every time I was on the boat and me, myself, and I eventually cracked the valve housing. The cracked valve would leak pretty good in the open position and leak slowly in the closed position. I called a boatyard for an estimate - about $735 for haul, breaking out the old valve and replacement - 2 hours of work. Yard said they didnt do replacement parts.

I emailed Forespar with pics of valve - got their part number - they sent me instructions on replacement the valve in the water - so for $85 (part and shipping) I replaced the valve in the water - sweet. The handle have a white plug - plug fits into the hull-side of the thru-hull. Insert the plug with a string on it and work on the valve. Pull the string and done.

Pic at top shows new assembly. White plug is seen with loop. Bottom pic is cracked valve removed.

Im sure you all know that but it was sweet news to me!

Re: Marelon Valve Replacement

PostPosted: Sat Nov 24, 2018 3:02 pm
by RichR
I am starting down this same path. My engine seawater intake marelon ball valve does not totally stop water in the off position. I started to change my impeller, but with the valve in the closed position, considerable water was still coming through. Flow is slowed down in the off position, but still coming in. Postponed the impeller change till I get this ball valve sorted out.

I wrote to forespar to see if there was any kind of adjustment or repair, likely. Got a response saying it will need to be replaced, and to send pics.

Re: Marelon Valve Replacement

PostPosted: Sat Nov 24, 2018 8:06 pm
by Camino
Right. How old is your boat? Forespar wants us to routinely exercise those valves.. I close my engine water intake and head intake every time I go out (weekly at least). The other marelon valves I exercise a couple of times a year (say 3-4x). Does your engine intake valve close all the way? An easy check of the condition of the valve would be to have a diver clean your bottom and while down there inspect the opening for debris or growth. If that’s not the problem, while he’s down there, have him plug the opening with he while plug (with a lanyard to pull out later). If that route, have your parts all ready with you...

Re: Marelon Valve Replacement

PostPosted: Sun Nov 25, 2018 5:40 pm
by GeoffSchultz
Don't you grease them monthly per ForeSpar's recommendation. Ha ha ha ha! You gotta be kidding me! Who does that?

-- Geoff

Re: Marelon Valve Replacement

PostPosted: Sun Nov 25, 2018 6:53 pm
by Camino
I’d like to hear! Haha. I keep a jar of the marelon lube stuff but use it on my speed paddle housing when I take that out and other more accessible parts!

Forespar recommends using their marelon lube on the ball joint moving parts - ie take the hose off and smear the lube on the ball and work it - possible in the water but better on the hard but in either case a real pita