PSS Shaft Seal - Bellows Degradtion

[RoyS]

As promised above, I checked mine today and discovered the same problem. I bought mine four seasons ago and it has the same cracked exterior. I did have a diesel tank leak last year that could have dripped down on the rubber bellows, however. The one before that lasted ten years without any deterioration.

 

[walmsleyc]

Yes, that looks about the same.

As promised above, I checked mine today and discovered the same problem. I bought mine four seasons ago and it has the same cracked exterior. I did have a diesel tank leak last year that could have dripped down on the rubber bellows, however. The one before that lasted ten years without any deterioration. View attachment 176474

 

[walmsleyc]

After removing the aft hose clamps (boat not in the water), as instructed by PYI, to reveal the date code on the bellows, I see a "13"/"10" which I would expect means October of 2013. I purchased the bellows kit in 2017, so that's already pretty old when I installed it.

So, anyone installing a bellows kit, check the date code before you walk away from the store.

If I hear any feedback from PYI about the age of the kit I will pass along, but the degradation

could be just age.

Chris

 

[smokey73]

Interesting that the area that has been shielded by the hose clamp looks pristine but the area that has been exposed to the atmosphere is cracked.

I wouldn't expect a lot of UV exposure where it is located in the boat.

 

[BillyK]

i wonder if there is anything we can spray or treat the bellows with to protect it..

 

[Ed Caldwell]

As promised above, I checked mine today and discovered the same problem. I bought mine four seasons ago and it has the same cracked exterior.

Maybe we can help PYI triangulate this. I just checked mine, installed as a replacement bellows in April 2016, and it's fine. I don't know the date code, but it was probably purchased in early 2016.

 

[RoyS]

I called PYI about my deteriorated bellows and its likely exposure to leaking diesel fuel from a 39 year old aluminum tank (since replaced). They concluded that exposure to petroleum products will in fact cause this condition. They also suggested more frequent visual inspections. I have ordered a replacement for mine. In my case we are blaming exposure to diesel fuel.

 

[smokey73]

[/QUOTE]

I called PYI about my deteriorated bellows and its likely exposure to leaking diesel fuel from a 39 year old aluminum tank (since replaced). They concluded that exposure to petroleum products will in fact cause this condition. They also suggested more frequent visual inspections. I have ordered a replacement for mine. In my case we are blaming exposure to diesel fuel.

Roy, If your's is cracked all the way around the whole surface of the bellows did it leak so much that it coated the whole bellows or are they attributing this to "vapors" from the diesel fuel? Do you know the date code on your bellows? Do they say "long term" exposure to diesel fuel or a single exposure? Doesn't seem like a leak like you describe should submerge the whole bellows and it doesn't seem like its a good idea to use a compound for the bellows that would degrade from a single exposure to a liquid that is used in common application on a boat should degrade the item. I think I remember someone writing that they tinkered with compounds for the bellows - did you two get one of the Opps! compounds? If you could get the date code from yours it would be greatly appreciated.

Also, are your bellows compressed as much as the ones posted here? I'm going to the boat today to confirm inspect mine but I think it is not nearly as jammed together. I wonder if that could have some impact on it?

I think we all are interested in the resolution of this and should make sure we really inspect those bellows closely. Thanks

 

[walmsleyc]

Regarding the amount of compression. I put 3/4" of compression from the relaxed position as per their instructions. It was actually quite difficult to get that done in such a cramped location. Sort of a 3 handed job.

Chris

Roy, If your's is cracked all the way around the whole surface of the bellows did it leak so much that it coated the whole bellows or are they attributing this to "vapors" from the diesel fuel? Do you know the date code on your bellows? Do they say "long term" exposure to diesel fuel or a single exposure? Doesn't seem like a leak like you describe should submerge the whole bellows and it doesn't seem like its a good idea to use a compound for the bellows that would degrade from a single exposure to a liquid that is used in common application on a boat should degrade the item. I think I remember someone writing that they tinkered with compounds for the bellows - did you two get one of the Opps! compounds? If you could get the date code from yours it would be greatly appreciated.

Also, are your bellows compressed as much as the ones posted here? I'm going to the boat today to confirm inspect mine but I think it is not nearly as jammed together. I wonder if that could have some impact on it?

I think we all are interested in the resolution of this and should make sure we really inspect those bellows closely. Thanks

 

[Justin_NSA]

This makes me appreciate the materials that my Lasdrop Gen II is made from. The hose is Trident Ply

Trident Ply marine wet exhaust hose for short, straight connections. In smaller I.D.’s for critical engine coolant & circulation, heat exchanger and discharge uses. Extra heavy tube and cover with 2 to 6 ply reinforcement resists heat, aging, ozone, exhaust and Diesel. Exceeds (SAE J2006-R1, and ABYC & NMMA P-1 exhaust standards). New Lloyd’s Registry Type Approved Cert. 02/00029. Black High Temp EDPM Rubber 280°F (138°C) Max.**

 

[dmax]

Same for me, walmsleyc, I had to have a second person provide the 3rd hand. What helped was that I also ordered the extra shaft collar (as a fail-safe) - we compressed the bellows as much as possible, tightened the shaft collar and used the shaft collar as a leverage point to compress the bellows further. I inserted a plastic scraper in between the shaft collar and what PSS calls the Stainless Steel rotor - this got the last 1/4". This was last year, unfortunately, I have to do it again this year as I have raised the engine up about 6-7" to access the oil pan and swap out the motor mounts. It's a PITA to put in but I love the dry bilge.

 

[Alan Gomes]

This makes me appreciate the materials that my Lasdrop Gen II is made from. The hose is Trident Ply

This makes me appreciate my old-school traditional stuffing box.

 

[Justin_NSA]

This makes me appreciate my old-school traditional stuffing box.

That too!

 

[JamesG161]

It may be over compression. Nitrile rubber should not crack like that.
You might measure the distance from rib to rib to verify the right compression versus recommended spacing.
Jim...

 

[RoyS]

To answer your questions: My diesel tank started leaking while stored over the 2018-2019 Winter. When I opened the boat up in the Spring 2019 I found about a gallon of diesel in the bilge. Some of that diesel could have leaked onto the bellows as that is directly under the edge of the tank platform. Tank bottom was weeping. Plywood platform was saturated. So the bellows may have been totally covered with diesel. Although I replaced the tank and cleaned up the bilge I did not notice the deterioration on the bellows until I looked for it a few days ago after reading this thread. As to bellows compression; Yes I recall some difficulty compressing the bellows to the specified amount. The specification requirement for compression may be too much. Will report the date code when I remove it (soon) but I purchased it from Defender in December of 2015 for installation Spring of 2016. I suspect that Defender stock is always rotating and fresh. Hate that job.

 

[smokey73]

Same for me, walmsleyc, I had to have a second person provide the 3rd hand. What helped was that I also ordered the extra shaft collar (as a fail-safe) - we compressed the bellows as much as possible, tightened the shaft collar and used the shaft collar as a leverage point to compress the bellows further. I inserted a plastic scraper in between the shaft collar and what PSS calls the Stainless Steel rotor - this got the last 1/4". This was last year, unfortunately, I have to do it again this year as I have raised the engine up about 6-7" to access the oil pan and swap out the motor mounts. It's a PITA to put in but I love the dry bilge.

You probably already know this but be sure to use new, uncompressed, set screws for the ones that contact the shaft in both the Rotor and the Shaft Collar. The point "dulls" on them when you use them. You can use the previously used ones for the backup or upper set screw in each set screw hole.

 

[Mike Oldak]

I'm rebuilding my engine compartment since the steel iron supports have pulled away from the hull (84 H34). I've hired a real diesel mechanic to do much of the work for me, but he did find some problems. 1st - my the prior "diesel mechanic" didn't install it properly and it does need to be replace soon. He indicated that these do have a recommended life regardless. I think he said 5 years. Does anyone have the manual? 2nd- my exhaust hose was delaminating from the inside and 3rd the diesel return line was cracking at the connection to the engine. Actually good to have a dependable diesel mechanic look at the engine every few years.

 

[njlarry]

Replacing the shaft log seal could mean dropping the rudder to pull the shaft to replace or remachine the shaft to remove and replace the shaft coupler. If it must be done every 5 or even 10 years I 'll go back to a conventional shaft log.

 

[SG]

I'm rebuilding my engine compartment since the steel iron supports have pulled away from the hull (84 H34). I've hired a real diesel mechanic to do much of the work for me, but he did find some problems. 1st - my the prior "diesel mechanic" didn't install it properly and it does need to be replace soon. He indicated that these do have a recommended life regardless. I think he said 5 years. Does anyone have the manual? 2nd- my exhaust hose was delaminating from the inside and 3rd the diesel return line was cracking at the connection to the engine. Actually good to have a dependable diesel mechanic look at the engine every few years.

Replacing the shaft log seal could mean dropping the rudder to pull the shaft to replace or remachine the shaft to remove and replace the shaft coupler. If it must be done every 5 or even 10 years I 'll go back to a conventional shaft log.

Eventually the bellows get less elastic. That's the issue.

I had our PSS seal replaced because of an "abundance of caution" concern by my diesel mechanic. You can replace the bellows themselves, but the difference in the cost and labor is not great enough to justify no just replacing the whole unit.

This as after about 12 years. It's was done as part of the bottom repainting that we due every couple of years.

I would think that the real service life is much longer than 12 years. Of course if you have a ozone anti-mildew device or some unusual chemical cleaning process going on in the engine compartment, it might be different.

Eventually the bellows get less elastic. That's the issue.

 

[RoyS]

So I replaced my bellows after I found cracks similar to those reported in the beginning of this thread. In my case, as stated earlier, I did have a diesel leak that could have saturated and damaged the bellows. However, the date code on my cracked bellows is 10/13, exactly the same as the original poster's! Possible there was a defective materials problem at that time. In my case it was an extremely difficult job to replace due to having to pull the shaft coupling in a near inaccessible location. Anyone else have this cracking bellows problem? If you installed your bellows any time after 10/13 you should take a close look. The replacement bellows that I bought last week from Defender was actually manufactured in 4/17, three years ago.