Seacock jammed-gctid364234

[Guest]

After replacing the pump on the head I cannot get water to flow in through the seacock. The seacock lever moves OK, but no water comes in whatever the position. Is it possible for the internal shaft to shear? It would be nice to be able to fix this without a haul-out. Boat is a 1988 3218.

Any suggestions?

[Guest]

What is the seacock manufacturer and type giving problems?

[mmichellich]

pedvictoria wrote:
After replacing the pump on the head I cannot get water to flow in through the seacock. The seacock lever moves OK, but no water comes in whatever the position. Is it possible for the internal shaft to shear? It would be nice to be able to fix this without a haul-out. Boat is a 1988 3218.

Any suggestions?

Did you try pouring water in the head to see if the new pump would pump it out? I always use something like Vaseline on pump O rings in pump when overhauled to make it work initially. New pump may not be primed. An easier problem than a broken thru hull.

[Guest]

You may simply have something stuck in the strainer or some organisms growing over the strainer. Remove the hose from the seacock, with it closed and and slowly open it and see if water comes in. If not try flushing it out with water pressure from a hose or stick something down with it open. I had the same issue and after cleaning it out with a long stick, it worked fine. I then installed a vacuflush because I hate raw water heads.

[RDOIII]

maybe simple question but are you sure the water is not shut off at the toilet from the repair?

Have you remove a hose from the seacock to be sure no water is coming in?

[Guest]

and please remember, you can remove the hose and allow water to come in for quite a while before you really have anything but a mess to worry about.

[Guest]

I will check to see what model the seacock is tomorrow - take a picture too.

The head itself pumps out fine. With the input hose disconnected, I tried blowing into the hose - definitely blocked.

[Guest]

wingless wrote:
What is the seacock manufacturer and type giving problems?

Here are pics of the seacock - I think the shaft must have sheared as the handle turns easily.

Attached files http://baylinerownersclub.org/media/...28_1.jpg[/img] http://baylinerownersclub.org/media/...29_1.jpg[/img]

[Guest]

Typically, a seacock has some amount of resistance when it is opened or closed due to the internal seal and bushing. If it turns easily, you may well have a stripped shaft. You might try removing the handle and turning it with pliers or vise grips.

[Guest]

mmichellich wrote:
Did you try pouring water in the head to see if the new pump would pump it out? I always use something like Vaseline on pump O rings in pump when overhauled to make it work initially. New pump may not be primed. An easier problem than a broken thru hull.

+1

Sometimes it needs to be a bit primed.

[Guest]

pedvictoria wrote:
Here are pics of the seacock - I think the shaft must have sheared as the handle turns easily.

Thats fairly unlikely, my seacock turns fairly easiy also.

[Guest]

wingless wrote:
What is the seacock manufacturer and type giving problems?

pedvictoria wrote:
Here are pics of the seacock - I think the shaft must have sheared as the handle turns easily.

Thanks for the pictures.

This is the http://www.apollovalves.com/_literat...Apollo catalog. Your part looks similar to their 77-100-10 series on page 4.

It might work to remove the stem for inspection. It might cause a big problem.

That part appears to have degraded from a seawater leak at the hose.

On mine, I disassemble the stem, clean the parts, lube them w/ marine grease and reassemble whenever I haul the boat.

The actuation effort on mine is similar to a wall light switch.

[ksanders]

Wow, I'm suprised nobody caught this.

That does not appear to be a legal seacock.

Perhaps I'm wrong but that appears to be a standard ball valve which would have NPT threads.

The through hull has straight threads.

These thread types while close are not the same and can lead to failure and sinking.

If it were me I'd replace that unit with a proper seacock that has the proper threads. The seacock should have a flange that screws to the pad in your photo.

If anybody has a contrasting opinion of this installation, please do not hesitate to chime in. I'm all ears.

[MalNSF]

I had a similar problem with my engine seacocks. After looking at the picture, my advice is: put down your tools and haul out. Rebuild or replace all of your seacocks at once. In the big picture, it is cheaper than the alternative. I tried removing the handle and adjusting the valve myself in the water. All I ended up with was a bigger drip and a faster trip to the yard.

, how can you tell the threads are different just by looking at the picture. I am not questioning you, I just want to learn what you see so that I have the knowledge for myself. So much to learn...

Thanks and good luck.

Jeff

[ksanders]

MalNSF wrote:
, how can you tell the threads are different just by looking at the picture. I am not questioning you, I just want to learn what you see so that I have the knowledge for myself. So much to learn...

Thanks and good luck.

Jeff

OK, no issues...

Look at the threads coming out of the hull

See the nut against the hull?

Those are straight threads. If they were tapered then you'd never be able to get that nut down against the hull.

Thats because tapered threads are approx the same length as the diameter.

Now look at the valve.

See any means of keeping the valve from twisting and coming off on its own?

If the valve had straight threads then it would be loose and could just come off or twist with normal boat vibration.

Thats why seacocks have a flange where they meet the hull. That way you can screw them in so they don't twist.

Seacocks generally have NPT threads on the interior side so you can connect a barb or other piping to them and it won't come off.

This is a common problem on boats. People think that just because you can get a NPT female valve to engage the threads on a NPS mushroom, its OK. What they don't realize is that the threads do not engage properly, and that you can only get about 1/2 the thread engagement that you could get with a proper NPT-NPT fitting. This makes the junction between these two dissimmilar threads a failure point. When it fails, the boat generally sinks very quickly because there is no way to stop the flow of water.