Pss shaft seal occasionally leaking

[swisscraft]

Hi,

I have a PSS shaft seal, it worked flawless the last two years ( I guess it's overall 8 years old). Now, sometimes when I start to run the engine after a few day at anchor it sprays water like hell. But not always. Most of the time is works as designed. I can stop the flow by moving the rubber gasket a bit by hand. Problem is I'm currently in the bvis and replacement is not that easy. Any idea what could cause that since its working most of the time perfect? The shaft is not moving sideways at all.

Thanks for any advice!

[sailvayu]

It is likely the pressure on the seal is not what it should be. The flexible hose should have some pressure on the seal. I would try sliding the seal back on the shaft some maybe a 1/4" or so. There should be a couple of set screws in the ring on the shaft that you can loosen to slide the seal back against the hose end. Most shafts have some movement back and forth when shifting I would check this as well. Too much movement could be a sign of other problems. likely the seal just slipped up the shaft or the boot is a bit compressed and not "pushing" on the seal like it should. Go to the PSS site for more info on setting it up. Finally you can check for contaminates as oils will effect the seal. It may need cleaning. Good luck

[Khagan1227]

I would be my opinion that either the seal has slipped on the shaft and the bellows is no longer pre-tensioned, the seal face has a gouge in it or the bellows has a tear.

I'm not sure if you are familar with the pre-loading of the bellows, but the procedure should be in your owners manual if you have one.

[noelex 77]

The bellows gradually loose their elasticity and the seal eventually needs replacing.
I Would look at replacing it at the next haul out.

In the meantime there are a few things you can do
Clean the carbon face, some debris trapped can cause leaks. Pull the bellows back (water will pour in) the water pressure will help get rid of any debris, but a clean with a cloth is worthwhile.

If this does not work move the SS face backwards a 1/4 inch at a time until the leak stops. Make sure you mark/ measure the position of he face, occasional a leak is simply caused by the SS face slipping forward, but you need a reference point to tell if this has happened. Put a hose clamp or anode to make sure the SS face cannot slip forward in the future.

Make sure therae is not another cause such as a broken engine mount or very poor engine alignment.

[Wainui]

I had the same thing happen to me when the seal slipped on the shaft. I have purchased a split collar from McMaster Carr and attached it to the shaft as a safety. I recommend to use this type of collar or even just a clamp as a back up and install a bilge pump alarm when useing a PSS seal.

Keep safe out there!
Mark

[swisscraft]

Thanks guys for all the quick feedback. PSS has not even answered the earlier send email - the cruisersforum is that fast!

I will try to clean the seal now and check again. I'm not yet sure how to move the stainless bracket back as the manual says not using the screws a second time. May have to check that or find a way to ship some screws to the BVIs.

For the other safety advice, I mounted a zink before the SS Bracket so I will not loose the thing in case. And of course, Bilge Alarm etc....

Thanks so far & I keep you posted.

[Geoff54]

Originally Posted by sailvayu

There should be a couple of set screws in the ring on the shaft that you can loosen to slide the seal back against the hose end.

There should be two set screws in each hole - the bottom one acts against the shaft and the top one locks the bottom one. If you only have one it can work loose. Also, they are meant to deform and be used ONCE. It is important that, if you loosen them, replace them.

EDit: looks like you know this already :-)

[chrisjs]

PSS advised me that you could switch the outer and inner set screws for re-use.
There are actually 2 set screws in each position.

[AnchorageGuy]

If you are in a situation where you need to adjust the SS collar and don't have the replacement set screws, reuse the ones you have, add the split collar Wainui shows for safety and get another set of set screws sent to you as soon as possible. After 8 years it's probably time to replace the bellows and seals. Chuck

[senormechanico]

Check your motor mounts.
They keep the motor in the correct spot fore and aft as well as every other direction.
If one or more are bad, it could affect the shaft seal.

[S/V Alchemy]

Originally Posted by chrisjs

PSS advised me that you could switch the outer and inner set screws for re-use.
There are actually 2 set screws in each position.

Well, I installed one yesterday and got the strong impression that the set screws were one-timers and that I should get me some spares.




Ignore the rust...it's from grinding stuff and will be cleaned up
The McMaster-Carr split-ring idea is actually pretty good. It's like a variant of putting a shaft zinc between the hull and the cutlass bearing to keep a busted shaft from "leaving".

[endoftheroad]

Great video.

PSS Install Video - YouTube

[cuthbert]

You might just need to "burp" the seal (google it) and give the face a quick wipe clean at the same time.

Noting that yours is 8 years old, I changed mine at 5 years because that it is pss recommended interval, my understanding is that if something of this nature (below the waterline) fails and you did not follow the manufacturers service/replace interval, the insurers get a free pass.

[sailorboy1]

Plan on getting and installing a new bellows. Do t on your own terms i.e. plan on it instead of waiting for it to go.

In the middle of the season last year my bellows started leaking. I had the same thing going on with leaks "sometimes". I tightened the by moving the rotating seal and then the bellows was spraying out. ........... Clue have some Rescue Tape handy.

[endoftheroad]

Originally Posted by Don L

Plan on getting and installing a new bellows. Do t on your own terms i.e. plan on it instead of waiting for it to go.

In the middle of the season last year my bellows started leaking. I had the same thing going on with leaks "sometimes". I tightened the by moving the rotating seal and then the bellows was spraying out. ........... Clue have some Rescue Tape handy.

I agree, it's definately not a "if it aint broke dont f$&@ with it" kind of thing.
I grew up hearing that phrase in a rural farming community, but when it comes to boating I look for potential problems before they happen.