Groco SV Seacock - how many of you still have them?

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Westiculo

Senior Member
Joined
Feb 27, 2017
Messages
271
Location
US
Vessel Name
Rose Mary
Vessel Make
42 Grand Banks Motoryacht - 1985
Quick poll here, how many of you out there still have the old Groco SV seacock with the rubber cone? Have any of you been able to find replacement cones?
I just bought lapping compound thinking I had bronze cones - not the case.
 
I have a box full that I plan to put on Craigslist. It was not so much that there was a problem with the seacocks; but some of the plywood “backing plates” behind them were deteriorating badly. They were also not bolted through the hull, as good practice dictates. So I took all 14 of them out and figured I might as well go back with newer model Grocos. (Parks still gets excited when I post this photo. :rofl:)
 

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I have a box full that I plan to put on Craigslist. It was not so much that there was a problem with the seacocks; but some of the plywood “backing plates” behind them were deteriorating badly. They were also not bolted through the hull, as good practice dictates. So I took all 14 of them out and figured I might as well go back with newer model Grocos. (Parks still gets excited when I post this photo. :rofl:)

Holy crap! That is exciting haha.
I'm taking mine apart to get a look at them in April; I'll let you know if I need any replacements.
 
I have these on our Defever. Looks like the cones are obsolete. At last haul out I took mine apart and greased them up and they work much easier now.
 
I have them as well for diesels (SV1000's) and generator (SV750). About a year ago I was going to replace with new Groco's. After talking to their support people I decided to take them apart and "rebuild". Basically cleaning them up and putting in new gaskets. The rubber cones were pliable, not dried or rotting and didn't have any flat spots (that was good as replacements were impossible to find). They seemed ok so I greased them all up and put back in place.

Now I sort of wish I had replaced. I have air leaks on both of the SV1000's. When I run at cruise RPM they empty down to 3/4 full. Increase RPM's and get increased air in the strainer. Don't know if they did this before as the boat was new to me at that time. Odd that it is both sides though. Makes me feel like maybe I did something wrong. Not sure what that would be though. Pretty simple "rebuild". Don't even like calling it that!
 
I have a box full that I plan to put on Craigslist. It was not so much that there was a problem with the seacocks; but some of the plywood “backing plates” behind them were deteriorating badly. They were also not bolted through the hull, as good practice dictates. So I took all 14 of them out and figured I might as well go back with newer model Grocos. (Parks still gets excited when I post this photo. :rofl:)

Yup, that was a memorable order!
 
There was a company that started making the rubber plugs after Groco quit but they only stayed in business a couple of years.
 
Parks, any more commonly dealt with way(s) for air to get in that you know of?
 
Parks, any more commonly dealt with way(s) for air to get in that you know of?

Strainer gaskets are the most common source of air getting into the intake system.

It could be that the rubber cones in your seacocks are worn out. When they get old they usually develop bumps where the rubber is squeezed into the openings when you tighten the T-handle. The bumps make it hard to turn. You can sand the bumps off and keep using them for a while, but it is a sign they are about done. The bumps show up in seacocks that spend a lot of time in the closed position.
 
Strainer gaskets are the most common source of air getting into the intake system.

It could be that the rubber cones in your seacocks are worn out. When they get old they usually develop bumps where the rubber is squeezed into the openings when you tighten the T-handle. The bumps make it hard to turn. You can sand the bumps off and keep using them for a while, but it is a sign they are about done. The bumps show up in seacocks that spend a lot of time in the closed position.

Thanks Parks. There is a slight dimple on them but I wouldn't call it a bump and they turn smoothly. Appear to have been left open most of the time over the years. I leave them that way. Again, just odd that both do the exact same thing at the same rate. Guess I should just take them apart, to the point I can while in the water, and reassemble and see. I believe the gasket sets are available at Defender or Jamestown. Can't remember which.
 
“When I run at cruise RPM they empty down to 3/4 full. Increase RPM's and get increased air in the strainer. Don't know if they did this before as the boat was new to me at that time.”

Wasn’t there a thread on this here or somewhere else? It seems to be a common occurrence on the GB
 
“When I run at cruise RPM they empty down to 3/4 full. Increase RPM's and get increased air in the strainer. Don't know if they did this before as the boat was new to me at that time.”

Wasn’t there a thread on this here or somewhere else? It seems to be a common occurrence on the GB

Most likely you are remembering one I started months ago, last summer maybe. Never solved the issue but haven't worked real hard on it. Doesn't bother my cruising as I don't go anywhere near WOT just 1800 RPM at most. Figured I would replace the old strainers/through hulls at next haul out. Reading this thread brought it back up so thought I'd ask again. Someone told me it may be leaking at the threads. Paint the threaded joints with liquid electricians tape and see if that helps find the leak. Would prefer to fix and save the $2,000! Everything is available except that rubber cone.
 
The big hassle I have seen with the rubber plugs were owners who were never informed the T handle had to be backed off before turning the seacock handle to a different position.

For longevity the old bronze taper style seem the only units that will go 1/2 a century with minor care.

IF nor operated often , they too enjoy the securing nut loosened .

A kindness for tapered bronze is to replace the 1/8 inch plugs with outboard SS grease fittings and hit them a squirt with waterproof grease when in the open position.
 
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Parks, any more commonly dealt with way(s) for air to get in that you know of?

I did my gaskets too. Strangely, they supply a gasket for the lid that goes over the basket, but don't have one between the top wingnut and that same cap. Air gets in between the nut and the cap. If you haven't already, put an o-ring in there and you might find your problem goes away.
 
Thanks. Mine have a nylon washer between the lid and the wingnut. I believe the paperwork shows that piece as standard with the unit but will check that as well. Thanks for the suggestion...
 
Still have the original 2 from 1970. One for head input 3/4 or 1/2 inch, other for head outflow 1.25" or 1.5".
I have had them apart 10 years ago, and they were fine. As in off boat for close examination.

Rubber was not worn out. They do not leak or let air get sucked in, not sure how that is possible seeing they are rubber and you tighten the side handle, the whole thing gets sealed. I have no plans on replacing them, good for another 50 years. They also dont get open and shut very much.
 
Still have the original 2 from 1970. One for head input 3/4 or 1/2 inch, other for head outflow 1.25" or 1.5".
I have had them apart 10 years ago, and they were fine. As in off boat for close examination.

Rubber was not worn out. They do not leak or let air get sucked in, not sure how that is possible seeing they are rubber and you tighten the side handle, the whole thing gets sealed. I have no plans on replacing them, good for another 50 years. They also dont get open and shut very much.

My are 1987. Taken apart in 2017, gaskets in rough shape so everything cleaned well and new gaskets installed on the wing nut cover, top/bottom of cylinder and one between the strainer and the through hull. New nylon gaskets between lid and wing nut. Rubber cone in good shape. Hit them lightly by hand with some 440 sandpaper for good measure. Air getting in both units port and starboard.

Like most of my boat mysteries, it is probably something simple, user (reassembler) error but geez, there just isn't much to them to goof up. Probably won't get to the bottom of it until I pull the boat again and take them entirely apart.

You are right though, they SHOULD last another 50 years.
 
My are 1987. Taken apart in 2017, gaskets in rough shape so everything cleaned well and new gaskets installed on the wing nut cover, top/bottom of cylinder and one between the strainer and the through hull. New nylon gaskets between lid and wing nut. Rubber cone in good shape. Hit them lightly by hand with some 440 sandpaper for good measure. Air getting in both units port and starboard.

Like most of my boat mysteries, it is probably something simple, user (reassembler) error but geez, there just isn't much to them to goof up. Probably won't get to the bottom of it until I pull the boat again and take them entirely apart.

You are right though, they SHOULD last another 50 years.

I dont recall having gasket on the wing bolt cover on mine?
I dont think its needed.
When the wing bolt is tightened, it presses a plate which presses the rubber, the rubber expands against the inside housing and its sealed.
Its quite technically ingenious and simple at the same time.

You can take them apart if you have room with boat in water, stuff a rag into the hole to slow down the water coming in. They can be greased with silicone grease, something like that. Regular grease might swell the rubber.
You can probably even repair the rubber surface if needed wtih Loctite s30 black roof rubber polyurthane, its good stuff and soft like the original rubber, if your handy, holds up underwater. If really scored up badly, coat surface, then wrap with something to hold its shape, maybe paper. When cured soak it to dissolve away the paper.

The rubber surface on mine was pretty good condition.
 
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I dont recall having gasket on the wing bolt cover on mine?
I dont think its needed.
When the wing bolt is tightened, it presses a plate which presses the rubber, the rubber expands against the inside housing and its sealed.
Its quite technically ingenious and simple at the same time.

You can take them apart if you have room with boat in water, stuff a rag into the hole to slow down the water coming in. They can be greased with silicone grease, something like that. Regular grease might swell the rubber.
You can probably even repair the rubber surface if needed wtih Loctite s30 black roof rubber polyurthane, its good stuff and soft like the original rubber, if your handy, holds up underwater. If really scored up badly, coat surface, then wrap with something to hold its shape, maybe paper. When cured soak it to dissolve away the paper.

The rubber surface on mine was pretty good condition.

The gasket is between the wing bolt cover and the lid on top of the cylinder, see #20 below. I would think it is absolutely needed unless you have metal surfaces so smooth/even they mate well enough to keep air out. Again, the cones aren't scored or extremely dimpled. I can close open easy as can be. Thanks for the comments. At this point I'm sort of beating a dead horse on this one...

Something just occurred to me, mine are SVS Series. Mentioned above are "SV". Are they the same? If not then I' talking a different product as shown in the pic.
 

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The gasket is between the wing bolt cover and the lid on top of the cylinder, see #20 below. I would think it is absolutely needed unless you have metal surfaces so smooth/even they mate well enough to keep air out. Again, the cones aren't scored or extremely dimpled. I can close open easy as can be. Thanks for the comments. At this point I'm sort of beating a dead horse on this one...

Something just occurred to me, mine are SVS Series. Mentioned above are "SV". Are they the same? If not then I' talking a different product as shown in the pic.

Thread is about Groco seacock with the rubber centers not Groco strainers. A strainer does need to be sealed with a gasket or sealer.

Here is a rubber centered seacock. The side cover by the handle has no gasket.
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The SVS1000 is a combo seacock and strainer. Seacock has rubber come. Sorry for the bother.
 
The SVS1000 is a combo seacock and strainer. Seacock has rubber come. Sorry for the bother.

oh, your picture did not show any valve.

How abut use a wetvac, put the strainer outlet under suction and see f you can figure out where the air comes in.
 

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Here is the full diagram and pic of what I am talking about. A wet vac...hmmm...didn't think of that one. Seems like that might be a little easier than trying to figure it out with diesels roaring away and wife driving the boat. Thanks for the suggestion!
 

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For the record, if anyone knows where I can get two of the rubber cones for the SVS series, 1000 and 750, I would REALLY appreciate you letting me know.
 
For the record, if anyone knows where I can get two of the rubber cones for the SVS series, 1000 and 750, I would REALLY appreciate you letting me know.
One place where the air can come in if the rubber cone is shot is on the handle side. Other side is a threaded T handle. Hard to imagine air drawn in there, and you would think the lower seacock would be dripping wet if it had a leak due to worn rubber cone. And it ought to at least be weeping in some sea water visibly if the lower seacock is bad.

Are you tightening up the T handle to seal the rubber cone tight to the housing?

Take some toilet bowl wax ring, dry the bronze seacock best you can, smear the wax all over the side handle cover, bolts, T handle threads, any where you think it might leak and see if it at least slows down the air coming in. That wax should stop any air being drawn in from somewhere.

I wonder if your rubber hose-clamp-water pump has a defect.
 
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The big hassle I have seen with the rubber plugs were owners who were never informed the T handle had to be backed off before turning the seacock handle to a different position.

For longevity the old bronze taper style seem the only units that will go 1/2 a century with minor care.

IF nor operated often , they too enjoy the securing nut loosened .

A kindness for tapered bronze is to replace the 1/8 inch plugs with outboard SS grease fittings and hit them a squirt with waterproof grease when in the open position.



I have the old barrel type too. 40 years old now just took them apart, lapped and greased, good for another 40, I hope.
 
The vessel we are about to purchase has a svs 1000, there is a pin hole leak in the fitting that attaches to the hose outlet of the strainer, there is a barb fitting that fits to the fitting that attaches to the strainer. Hope that makes sense. The leak is on the inbetween fitting.

I can not tell from the pic whether that is just a nipple coming off the strainer or if it is threaded. if threaded does anyone know the size. I'm hoping that it is threaded and I can just apply some heat and disconnect and replace w/ out the middle fitting... just replace w/ barb.

If the middle fitting is soldered/welded on then I will have to replace the whole thing. If this is the case does anyone have recommendations on a replacement? Is this a thru bolted thru hull/strainer? Or is it just screwed onto the thru-hull w/ sealant?

Worse case is grinding out the whole thing and redoing the thru-hull and strainer. Just trying to avoid that.

Thanks in advance :)
 
NVM figured it out... it's threaded. Easy fix!
 
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