Marelon Valves Repairable? - Leak Through Stem

zeehag · Jul 26, 2009

rardiH36 said:
Not asking for specific instructions here, but I would like to know if Marelon hull-through valves are repairable. The Marelon website doesn't mention.

The large 1 1/2" (expensive to replace) galley sink drain valve leaks through the handle valve stem when in the open position. For my next haul-out, just want to know if the valve can be dismantled for (say) replacing O-rings which I presume might be in the valve stem cylinder.

regards,
rardi

is it leaking at the hull or is it leaking at the seacock??

tsmwebb · Jul 26, 2009

rardiH36 said:
Not asking for specific instructions here, but I would like to know if Marelon hull-through valves are repairable. The Marelon website doesn't mention.

The large 1 1/2" (expensive to replace) galley sink drain valve leaks through the handle valve stem when in the open position. For my next haul-out, just want to know if the valve can be dismantled for (say) replacing O-rings which I presume might be in the valve stem cylinder.

regards,
rardi

Yes. They have an "O" ring at the stem and it can be replaced even in the water... But maybe not for the faint of heart. Before going that route I'd try tightening the handle up a tad. Just remove the Forespar label and a screw head will be revealed. Tighten it A VERY SMALL AMOUNT. Make sure everything rotates freely and see if that solves your problem. Also you should get in the habit of greasing them. On the bench they're quite easy to break apart for inspection and lubing.

--Tom.

zeehag · Jul 26, 2009

find a brave diver with a toilet plunger--- have that diver stand by while you do the tightening just in case---oh yes--have spare part at hand prior to tightening, just in case....gooood luck.....toilet plunger keeps out the incoming water......in case ye needs to replace the parts in water--makes it a world easier.....

Bob J. · Jul 26, 2009

Carefully give the packing nut a 1/4 -1/2 turn where the stem comes out of the valve body.
If it's a typical ball valve, that should solve your problem.

Bob

Stu Jackson · Jul 26, 2009

Just be aware

of this: http://c34.org/bbs/index.php/topic,2729.0.html

I haven't had problems with mine, but DON'T unscrew the handle!

tsmwebb · Jul 26, 2009

Stu Jackson said:
of this: http://c34.org/bbs/index.php/topic,2729.0.html

I haven't had problems with mine, but DON'T unscrew the handle!

Man, that's scary. I have adjusted mine in the water -- but always with the handle in the off position. I just disassembled a 3/4" Forespar valve and honestly I don't see how it can leak through the stem with the valve in the off position unless the main "O" ring has previously failed. The stem doesn't hold the main O in place. I've tried to get mine to leak from either end by blowing into it with the handle off (in the off position) with no luck... I'll hook it up to town pressure tomorrow and see what happens.

--Tom.

zeehag · Jul 27, 2009

ihad my engine intake thru hull replaced in th e water--took 2 days and 4 men int he water to do this--was redefined worst case scenario---cost a lot of money. was bronze---but yours sounds like just the seacock is bad--is replaceable int he waer. have a diver with a plunger and have the plunger keep the water out---compress it against the hull of your boat at the thru hull. twist off the seacock and replace--rebuild later and keep if you need to save dough..but it sounds like the valve is in need of being addressed--it will only get worse----isnt difficult to get done in the water and wont sink your boat-----i think groco are the only rebuildable valves--or are there others??

tsmwebb · Jul 27, 2009

rardiH36 said:
Yesterday, I did tighten the valve handle screw. Just a modest effort yielded about 1/4 turn. I then observed the valve in the open position for a couple of minutes. No moisture at the valve stem/handle interface....

Great. I just hooked one of my 3/4 inch valves up to town water and removed the handle with it in the off position and it didn't leak with the water hooked up to either side of the valve. I've got pictures and if I can figure out how to get them onto this computer I'll upload them. Didn't test with the valve open as I didn't want to drive a bung into the valve and didn't have a cap for it... But I suspect it would blow up... So, my feeling is that if you're going to muck around with the handle you should do so with the valve in the closed position. And, of course be very gentle as the SS fastener can easily strip out the plastic... I also leave mine in the off position when not in use on general principles...

--Tom.

zeehag · Jul 27, 2009

tsmwebb said:
Great. I just hooked one of my 3/4 inch valves up to town water and removed the handle with it in the off position and it didn't leak with the water hooked up to either side of the valve. I've got pictures and if I can figure out how to get them onto this computer I'll upload them. Didn't test with the valve open as I didn't want to drive a bung into the valve and didn't have a cap for it... But I suspect it would blow up... So, my feeling is that if you're going to muck around with the handle you should do so with the valve in the closed position. And, of course be very gentle as the SS fastener can easily strip out the plastic... I also leave mine in the off position when not in use on general principles...

--Tom.

if is your pressure water--use a secondary pressure regulator...we had them blow out at a dock i was at in lost angeles yrs ago....i donot use pressure water anymore.....

tsmwebb · Jul 27, 2009

zeehag said:
if is your pressure water--use a secondary pressure regulator...we had them blow out at a dock i was at in lost angeles yrs ago....i donot use pressure water anymore.....

Thanks. We don't take any dock water into the boat. I took the whole rig out to the dock tap for testing. I figured town water pressure was a lot higher than anyone is likely to see in a through-hull so it would make a good test...

--Tom.

tsmwebb · Jul 27, 2009

Wanted to add this partly to show that the handle didn't leak when hooked up to town water pressure (which came as a relief to me) and partly to illustrate which Forespar valves I'm talking about -- these are the ones you can buy retail. I hooked the hose up to both ends of the valve and with it in the closed position the stem didn't leak at all. If the handle falls off and the valve leaks I'd suggest sticking the handle back on and closing the valve before looking for the O ring and attempting to reassemble things.

--Tom.

zeehag · Jul 28, 2009

gooood work!!!!!