Leaking Seacocks!!!

[bobmcd625]

My Volvo D2 40F engine, only two years old, was recalled due to issues with emissions standards and I just had the swap made. Before returning the boat, the Volvo dealer told me that they had noticed that the two main seacocks were leaking a bit. (See attached photo) These are for the cooling water">engine cooling water and a cockpit drain. The leak is just a drop every 3 or 4 seconds, so is not a danger, but still I want to fix it. I have tightened the nuts as much as possible, but the drops continue. I fear I'll have to haul out and take the valves apart to reseat the valve cylinder but just wonder if anyone has other solutions that don't require hauling out.

[billknny]

How is it that the dealer who is on the boat for a few hours notices this and the owner hasn't?

Looks to me like the wood base of the smaller one is very seriously compromised. Guess it has been leaking for a while, and needs a lot more work than just tightening the plug.

And is that really a sheet metal screw driven into the hull to attach a cable clamp???? Really?

It is possible--risky--but possible to drive a wooden plug in from the outside of the hull, and then properly fix the seacock. But you need to be sure you know what you are doing and can fix it right the first time. But the wood that need replacing on the one NEEDS a haulout to do right.

[bobmcd625]

Well, you are right, I should have spotted it sooner. The dealer had to remove the cooling water hose so got much closer to the valve than I ever did.
The cable clamp is not screwed into the hull, but into an inner lining. If you look more closely at the valves you'll see the cutouts in the lining.
It's still not clear how the leaks developed. There is very little movement on those valves.
Yes, a haul out is probably needed, but i'd still like to know the process for fixing the valve. I have heard that one removes the cone and uses a grinding compound like for grinding valves on a gas engine. Any constructive comments will be appreciated.

[Tailwheel]

Oh, fixing the valve is easy: once you haul out, remove the tapered plug, clean it and the tapered housing, then smear lapping compound (auto parts store) on the plug, reseat it, and - while holding it in the housing - turn it four or five times to allow the compound to do its job. Then pull the plug out and inspect it to ensure it is uniformly shiny. If it is, then it’s time to thoroughly clean the parts, slather them in axle grease, and reassemble. If it isn’t, then keep turning the plug until it’s uniformly shiny.

[Orion Jim]

Originally Posted by bobmcd625

Well, you are right, I should have spotted it sooner. The dealer had to remove the cooling water hose so got much closer to the valve than I ever did.
The cable clamp is not screwed into the hull, but into an inner lining. If you look more closely at the valves you'll see the cutouts in the lining.
It's still not clear how the leaks developed. There is very little movement on those valves.
Yes, a haul out is probably needed, but i'd still like to know the process for fixing the valve. I have heard that one removes the cone and uses a grinding compound like for grinding valves on a gas engine. Any constructive comments will be appreciated.

These are the best tutorials you will find on seacocks and backing plates. The use of a proper seacock grease is strongly recommended. Axle grease is great for axles.

https://marinehowto.com/category/plumbing/

[bobmcd625]

Thanks, Tailwheel and Orion Jim for your advice. I really like the Marine How To website. Was not aware of them. I am pretty well resigned to a haul out and proper repairs. I think the valves themselves can be retained, but even they may have to be replaced. Oh well...

[Tailwheel]

Hey Bob, I have heard that tapered plug type valves are the best there is. Try to hang on to them if you can.

Regarding hauling: a short haul may be an option. Ie: haul, lower into blocks, keep in slings. Then relaunch. Another option is to careen, or even partially careen, ideally while leaning against some pilings.

[bobmcd625]

Tailwheel...Yes, I'll try to keep those plug valves. They should last a long time with proper maintenance. Lapping the seat seems simple enough, but replacing the backing plates might be a challenge (for me). I'll discuss with my friendly boat yard to see what they say!

[Lepke]

I've taken these apart in the water. If you have a bilge pump and work fast, it's not that big of a deal.

Whenever you do it, grease with wp grease. I put a zerk fitting where one of the plugs are. Usually a couple pumps, turn the valve 180°, a couple more pumps. Maybe more the first time. I do it once or twice a year. The pressure isn't that great so the grease makes up for small imperfections in the valve. Might even work with your problem now. Sometimes you have to slack the valve nut to get the grease to flow. Some people file a small groove in the valve so the grease travels toward the ends. And I keep a grease gun with wp grease for valve maintenance and some old style water pumps.
The grease doesn't hurt anything after the valve. I've been doing it since the late 1950s that way w/o problems.

[bobmcd625]

Thanks, Lepke, for the comments on greasing. I like the idea of a zero fitting. I admit that I have not done any greasing but should. I will do some now to see if that helps. I would not trust myself to take out the valves while the boat is in the water. I can imagine plugging the thru hulls from the outside, but one of them is the type with a strainer so plugs won't work.

[BlackHeron]

If you do replace the cocks consider marelon plastic valves. I know many folks don't like the idea, but we have all marelon valves on our boat now with only one bronze cone type. I hate that cone valve, it is a serious PITA compared to the marelons which are like heaven. We shut off all the cocks on our boat every time we leave for anything more than an ice run to shore. So they get exercised almost daily except for the cockpit scuppers which obviously can't be shut off in case it rains. We try to exercise those at least once a month too.

That darn bronze one is always locking up tight. I've had it apart multiple times, lapped it and greased it. But sooner, rather than later, it starts getting stiff and giving me trouble, while thr marelons are trouble free year after year. We put marelube grease in them once a year or so or whenever we haul out.

W e have a plastic hull, why the big deal about plastic valves. Marelon is tough glass-reinforced material. Just as strong as the hull.

[Lepke]

I should add, most of my seacocks date from when the boat was built 1942. Disassembled and regreased at haulouts, and still in excellent shape.

[bobmcd625]

Good thought BlackHeron. Totally agree that one should look at synthetics. The pressures are not great at all so why not. Thanks for the tip.