PSS Type A Shaft seals VS Tides Sure Seal 2 1/4 inch

Carpediem44DB

Carpediem44DB

Well-Known Member
Aug 18, 2015
3,230
Sanfransico Bay area
Boat Info
2000 Carver 506
2006 44 DB Sedan Bridge
Engines
Volvo TAMD 74 P
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Does anyone have good advice regarding shaft seals? These PSS seals are 6 years old and were adjusted in July of 2019 about 60 hrs running time since. The Starboard seal leaks at speed 16oo and above on sea trial. PSS recommends assembly replacement at 6 years and these are right at 6 years old. The yard foreman assigned to my WO says he sees them last up to 15 or 20 years and suggests perhaps cleaning and adjustment based on over all condition might just be in order. The mechanic has yet to see them. I removed the battery shelf and cleaned the shafts up and moved the rotor back so he can inspect them and make his recommendation. I had Tides Marine Sure Seals on my 44 and for five years and 400 hrs never had a drip out of them and I liked the idea that should I have had an occasion to replace a seal I could just install the one in the spare carrier on the shaft. I'm interested in your experience as to life limits on the PSS or whether you might consider replacing with Tides Marine seals.
Thanks Guys
 
I prefer the Tides design over the PSS. My 390 came with the "old" Tides Strong Seals and in 10 seasons they still have not leaked and the spare seals are still in there carriers in front of the originals. I've seen a few PSS seal fail and leak pretty badly and require emergency haul outs. Just my opinion.
 
PSS is a mechanical seal and Tides is a lip seal.

A few things can make the PSS leak. Something caught between the seal faces. Or weakening of the bellows causing the compression of the faces. Serious missalignment can cause an issue as well as you'll get gaps between the seal faces. Look at the seal faces. They should be smooth. Make sure there are no knicks or scratches, etc. When you reassemble, make sure you put the seal face down a little further to create more pressure to keep the faces together. See if that helps. On a lightly used boat, I think they should last more than 6 years.
 
Have had both on our GB. Based on our experience I prefer the Tides. I've fought with PSS "spray" a couple times since installation after Tides started leaking (1300 hours) and I replaced them with PSS which we have run for 2000 hours but used three seals. Also, once you have PSS, the shafts can be "knicked" from the set screws and not smooth enough for lip seals. Don't ask me how I know this....
The 6 years is based on bellows deterioration which can obviously be a catastrophic failure. Make sure the bellows seem supple and flexible and not subject to splitting.
 
Thanks Guys, We have decide on replacing bellows since it is on the hard now. I offered to do it myself but the seller insists on paying for it and having the yard do it incase there are any problems in the future.
Cheers
 
If you replace the bellows and not the rest of the parts, make sure you get 1200 grit paper and hone the surfaces of the collar and plastic surface. Wet the paper and couple side down making small circles with both pieces. The wet sandpaper should be on a nice piece of granite - a counter top can be used. If there are any nick's in either face start with 800 grit.
 
Both seal assemblies are well renown and have stable markets. Both when is good repair operate leak free. The Tides assembly in my opinion when things do go wrong is a better concept. First the Tides can tolerate loss of cooling water better than the PSS due to the differences in seals. The carbon to Stainless mechanical seal that PSS uses is critical to cool and lubricate with water at any shaft speeds above dead idle; the Tides on the other hand require cooling water for the Delrin bearing but that material is pretty much self lubricating much like Teflon. The Delrin bearing is used to center the seal assembly on the shaft so the lip seal does not have to accommodate any shaft wobble; consequently a perfectly straight shaft and properly aligned seal bellows and that Delrin bearing is essentially not required. The Tides lip seal is a standard seal one would see in any machinery albeit made from CRES.
But, the big advantage to the Tides assembly is the ability to change the lip seal in the water and that a spare can be maintained on the shaft. So, for me when in remote locations the Tides is the selection..
 
If the PSS required complete replacement rather than just the bellows, I would probably have gone with Tides. I see this boat being a five to seven year boat for us doing mainly bay and delta with occasional short coastal cruising. If we are still into the boating life after that then this boat will be replaced with a 65 pilot for longer hauling so reliability will be foremost then. Thanks for the input.
Carpe Diem
 
Ater 17 years the starboard Tides has begun to drip. I'm going to replace with the same.
 
I have worked on both Tides and PSS but I have PSS on my own boat. I installed them in 2002 and they have not leaked a drip but I am in Fresh or brackish water most of the time.

Yours look a lot older than 6 years. I would make sure that the cooling hose is not the source of your leak. The pressure in that hose at idle is minimal but as the rpms increase....it will see 6-8psi. If it isn't the cooling hose....then the carbon ring maybe cracked. That happens when the cooling hose is clogged and the surface heats up.

A few more photos of the carbon surface would help possibly identify the problem. Your mechanic can pressurize the cooling hose with water to see where the leak is.
 
We replaced the bellows only and that took care of the leaking. Even though they were just six years old they were a good 2 1/2 inches shorter than the new ones when removed.
 
Carpediem44DB said:
We replaced the bellows only and that took care of the leaking. Even though they were just six years old they were a good 2 1/2 inches shorter than the new ones when removed.
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I don't know if my PSS's were original but I know of 12 years for sure that I got out of them. I burped them a couple of times over the years and then last year with couplers, shafts, cutlass bearings, & props it was time to replace them. PSS is located close to Everett where Boeing has the largest warehouse in the US so I stayed with them supporting our local business.
 
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