PSS Dripless Shaft Seal Maintenance

How long can I expect the rubber bellows on my PSS Shaft Seal to last?* Mine is working perfect, no drips, but I have noticed what looks like a crack in the rubber. I pushed it a bit with my hand and it is only on the surface.* I plan on changing it during a Spring/Summer haulout.**

Has anyone had one fail?*** JohnP

Mine looks pristine after 4 years, but I gather replacement is supposed to happen when you notice the first checking on the surface.

A Stack of Invoices from the PO reveals that the PSS Shaft Seal was installed during the Spring of 2004.** Does not seem too old.* Contacted the PSS people they sell a maintenance kit* includes o-rings and bellows for about 125.* Not too Bad.

PSS recommends the bellows be replacement every seven years, I believe. But I have personally seen some that were ten or more years old that were perfectly good. I have installed hundreds of these and never had one fail. We have one in our boat now. Chuck


-- Edited by Capn Chuck on Thursday 20th of January 2011 05:47:00 PM

We have friends that had one that failed. PSS paid for the haul out. Luckily they were near a yard.

A friend of mine had one fail. It was about 8 or 9 years old.
The failure eventually (the following year) took out his starter and tranny due to corrosion from the salt water that was in his bilge.

jleonard wrote:

A friend of mine had one fail. It was about 8 or 9 years old.
The failure eventually (the following year) took out his starter and tranny due to corrosion from the salt water that was in his bilge.

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********** I suppose these "failures" happen underway with the shaft and coupling flinging water everywhere.* I think next trip to the boat I will measure the diameter of the shaft log so I can order a new bellows.** JohnP

*

"*I suppose these "failures" happen underway with the shaft and coupling flinging water everywhere"

Actually this one*was discovered *while the boat was on his mooring. It may or may not have failed initially underway, I don't know. Regardless, on this particualr boat the stuffing box was well away from the engine compartment. The corrosion was because there was so much water in the bilge. It "may" have been leaking for a few weeks un noticed.

jleonard wrote:

"*I suppose these "failures" happen underway with the shaft and coupling flinging water everywhere"

Actually this one*was discovered *while the boat was on his mooring. It may or may not have failed initially underway, I don't know. Regardless, on this particualr boat the stuffing box was well away from the engine compartment. The corrosion was because there was so much water in the bilge. It "may" have been leaking for a few weeks un noticed.

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********* Do you know if the rubber bellows cracked or did something else wear out?

********* Good thing the pumps and batteries held up or it sounds like she could have gone down.* How did they keep the batts charged on a mooring?**

********** JohnP

*

*"Do you know if the rubber bellows cracked or did something else wear out?"

The bellows failed. I think the initial leak was slow so probably the pump wasn't going crazy for a while.
When the boat started to pump a lot one of the yacht club members saw it and called Mark who was actually the commander or whatever the guy in charge is called. Since he is local he went*to the boat that day before the batteries crapped out.*
The really big isue was the eventual corrosion of the starter and tranny (including damper plate) the next year. They went out one a time and of course at the worst of times, when the Admiral was aboard. He got to know the towboatUS guy really well that summer.

jleonard wrote:

*"Do you know if the rubber bellows cracked or did something else wear out?"

The bellows failed. I think the initial leak was slow so probably the pump wasn't going crazy for a while.
When the boat started to pump a lot one of the yacht club members saw it and called Mark who was actually the commander or whatever the guy in charge is called. Since he is local he went*to the boat that day before the batteries crapped out.*
The really big isue was the eventual corrosion of the starter and tranny (including damper plate) the next year. They went out one a time and of course at the worst of times, when the Admiral was aboard. He got to know the towboatUS guy really well that summer.

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********** Thanks for the info.* Too bad he salted up his whole engine room.** Thats something worth avoiding!!!!!!!!

*

Ours sheaft seals are about 7 years old, and still look like new. On the other hand, last summer while working on a Seapro oil spill response boat, I noticed the bellows on both shafts had severe cracks. I understood they were about 5 years old.**

In my damage control kit, I carry a couple wax toilet rings.* That wax is some of the stickiest stuff I have ever had the misfortune to handle, and if I ever had a shaft seal failure, I think I could stop the water by wrapping the bellows with wax, covered with something like grease tape (also in our kit) topped off by perhaps duct tape.*

Failure of the bellows has the potential to let in a huge amount of water in a short time. Another good reason to have a high water alarm.* Don't forget to check the hose clamps at least once a season. Make sure they are tight, and corrosion free..............Arctic Traveller

Arctic Traveller wrote:

Ours sheaft seals are about 7 years old, and still look like new. On the other hand, last summer while working on a Seapro oil spill response boat, I noticed the bellows on both shafts had severe cracks. I understood they were about 5 years old.**

In my damage control kit, I carry a couple wax toilet rings.* That wax is some of the stickiest stuff I have ever had the misfortune to handle, and if I ever had a shaft seal failure, I think I could stop the water by wrapping the bellows with wax, covered with something like grease tape (also in our kit) topped off by perhaps duct tape.*

Failure of the bellows has the potential to let in a huge amount of water in a short time. Another good reason to have a high water alarm.* Don't forget to check the hose clamps at least once a season. Make sure they are tight, and corrosion free..............Arctic Traveller

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********* Good info.** I wonder if the fact that my boat was on the hard and covered thru at least one Summer before I bought her could have made the bellows crack early.

**********Well it is what it is.* I geuss it could have been stood on, something could have dropped on it, or maybe battery acid.* Never know,* I am sure the next one will be taken better care of, on my watch at least.*** JohnP

*

Went 8 years on the first PYI.* No issues, and bilge has been dry.

After 8 years, pulled the shaft for other reasons, and noticed some scratching on the rotor.* Had the rotor replaced, and put*new bellows in at the same time.

The bellows are also what supplies the pressure to seal the carbon stator to the stainless rotor. The bellows are compressed during installation.

I assume that over time the bellows soften and may lead to leaking at the sealing surfaces. At least that is what it looks like is happening on mine, I have ordered the maintenance kits, hopefully that solves the tiny leak.

Jeff/Artic Traveller - what a great idea.* That stuff is sticky for sure, and in a pinch, why not?

Our*were replaced*2003 and I plan on pulling the boat and having bellows/seals replaced*in June.* As a general rule I use 7 to 10 years for hoses and belts but check for checking/cracking yearly.* If we had a leak I would wrap in cellophane/Saran wrap and secured with emergency tape that stick to its self even when wet and/or oily.****


*
As a precaution I have a hose clamp around the shaft to keep the SS ring from sliding forward, and also caulked between the SS ring and the shaft in case the seal failed.* *Have a blue paper towel below the bellows so it they leak it will show and one of the first things I look at when entering the engine room.* Also installed double bilge pumps with alarms, one is*connected to*the house batteries, the other is on the back up start battery, and always leave the battery charger on.*

The wax ring is a good idea.*

Saran - another good idea Phil.* Has yours ever started to sling a drop or two?* I used the clamp as well, so it hasn't moved, but it has started to drip about one drop every 5 hours or so.* I was wondered if you ever observed that, or perhaps you aren't motoring as much as we do?

As long as the shaft is not moving it does not drip.* When the shaft is turning it leaks a bit. Maybe move the hose clamp back to put more pressure on the seal?* You could make a shower sump to the catch the water and pump the water over board.* I made our shower sumps out of small plastic container with a bilge pump with a self contained float, sitting in it. ****So are you going to the Sunday get together of the boat show.* If so maybe we can meet there or when you pass by Everett.

Phil Fill wrote:

*
As long as the shaft is not moving it does not drip.When the shaft is turning it leaks a bit. Maybe move the hose clamp back to put more pressure on the seal?You could make a shower sump to the catch the water and pump the water over board.I made our shower sumps out of small plastic container with a bilge pump with a self contained float, sitting in it. So are you going to the Sunday get together of the boat show.If so maybe we can meet there or when you pass by Everett.

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If the seal leaks, (at the junction of the two sealing surfaces) it's either too loose, in which case you can slide the sealing ring on the shaft aft a bit (each manufacturer has a specification that determines what the maximum bellow's compresson is).* If your at max compression, the sealing ring must be compromised.* I have in the past removed and re-machined the sealing surface. This was with the manufacturers blessing (this was a commercial vessel)* Failing that, replacement is indicated..............Arctic Traveller


*

Phil, Jeff, is it your experience that the bellows fatigues, requiring readjustment?* The manual doesn't say but that doesn't seem unreasonable.* This unit is 4 years old, so there are a couple of years remaining before PSS says to replace it regardless.* Perhaps I'll compress the bellows another quarter inch and see.

I won't be making it to the Sunday forum get together.* Wish I could, but I have a class to teach on Sundays that shoots most of the day.

Thanks guys...

I don't know if "PSS" is the same seal as "PYI". No one on this thread has said what "PSS" means. I've had PYI seals on two boats. I don't know what PYI stands for (it's the name of the company) and I don't like the owner of the company but I do use the PSS (I looked it up) seal and it's been flawless in it's performance EXCEPT on 2 different times it leaked while underway. In my Albin 25 near Friday Hbr I asked for a cup of tea and was informed by my 1st mate that the fwd cabin floor was floating. I quickly found water poring in at the shaft seal and fly'in around. The SS sleeve that is fixed to the shaft had slid fwd. It was a quick and easy fix w an Allen wrench. The same thing happened to us later so now I set the set screw hard enough to make a good mark on the shaft at just the right bellows adjustment and loosen it and slide it aft exposing the mark. Then I ctr punch the mark and drill into the propeller shaft close to 1/16" w a drill larger than the dia of the set screw. Then I install the sleeve w the set screw in red locktite. No problem since. I do use the water injection port and plumb it to seawater from my exhaust system. I bleed the air out of the stern tube and burp it from time to time. The water fed into the stern tube ensures plenty of water flowing through the stern bearing (cutless bearing). I don't think my PSS seal leaks at all. My PSS is 4 yrs old.

-- Edited by nomadwilly on Saturday 22nd of January 2011 12:00:26 AM

PSS = Packless Sealing System. PYI= (I think) Pacific Yacht Industries.* PYI sells PSS seals and PSS is a branded product trademarked to PYI Inc.* PSS seals are sold in 14 countries.* They are manufactured in the US, I believe by PYI themselves, but I could be wrong on this last bit.




-- Edited by Marin on Saturday 22nd of January 2011 12:43:13 AM

IF the unit was installed after the boat was built , it may be possible to scrap it and restore the shaft packing seal.

The modern Goretex and similar products solve all the problems the ceramic seals were supposed to solve , without the danger of rapid flooding.

A 40 year old "Solution" , that could put the boat in danger , is not an answer today.

FF wrote:

IF the unit was installed after the boat was built , it may be possible to scrap it and restore the shaft packing seal.

The modern Goretex and similar products solve all the problems the ceramic seals were supposed to solve , without the danger of rapid flooding.

A 40 year old "Solution" , that could put the boat in danger , is not an answer today.

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********* I have had these PSS seals on two boats and they do work well.* However I have had the standard packing gland on many boats and as long as the packing nuts are easy to get at they are simple to maintain and adjust. If the original had came with the boat (hidden in a locker somewhere) I would probably consider putting it back in use.*** JohnP

*

John P,
The small amount of leakage from a traditional shaft seal is of no matter and the seal itself acts as an additional shaft bearing. That would be of benefit only if it were aligned properly and that (of course) can only be accomplished by adjusting the position of the engine and gearbox. If the shaft is centered in the stern tube where the shaft seal would be located the traditional shaft seal is excellent. There may be (on some boats) an idler bearing in between the shaft seal and gearbox flange that is fixed and offers no adjustment. In that case the PSS seal is (in my opinion) a better choice. But the old waxed packing seal is more secure given a small bit of maintenance.

nomadwilly wrote:In that case the PSS seal is (in my opinion) a better choice. But the old waxed packing seal is more secure given a small bit of maintenance.

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I agree!

*

Arctic Traveller wrote:

Ours sheaft seals are about 7 years old, and still look like new. On the other hand, last summer while working on a Seapro oil spill response boat, I noticed the bellows on both shafts had severe cracks. I understood they were about 5 years old.**

In my damage control kit, I carry a couple wax toilet rings.* That wax is some of the stickiest stuff I have ever had the misfortune to handle, and if I ever had a shaft seal failure, I think I could stop the water by wrapping the bellows with wax, covered with something like grease tape (also in our kit) topped off by perhaps duct tape.*

Failure of the bellows has the potential to let in a huge amount of water in a short time. Another good reason to have a high water alarm.* Don't forget to check the hose clamps at least once a season. Make sure they are tight, and corrosion free..............Arctic Traveller

Click to expand...

There is an even more readily available ingredient that has been*used by SAR crews over here for decades to plug holes in sinking*boats. Butter/margarine will attach to* any wet or dry surface and will harden in contact with sea water.*I have*used it myself on an a couple of*call-outs to stop boats from sinking under my feet.

r-rossow,
"Butter/margarine will attach to* any wet or dry surface and will harden in contact with sea water."
Really!* How big of a hole will it plug? Is margarine or butter better?

nomadwilly wrote:
Really!* How big of a hole will it plug? Is margarine or butter better?

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back in the olden days they used to use tallow for gooping up salvage patches. They had to work fast though because the fish loved to eat the stuff and would gobble it up before the diver got the patch on.

Never heard of using butter or margarine though. Then again, who the heck has tallow these days?

*