Shaft seals needing ongoing attention?

Rivertender

Rivertender

Member
Nov 7, 2006
123
Tampa Bay
Boat Info
370 aft cabin S Ray 1997
Engines
Twin 454
Inboard
Had PSY (I think) dripless shaft seals installed in 2019.

Unable to use the boat hardly at all for several months due to wife's medical issues

Took the boat out finally and discovered the seals were leaking, so I called the yard and he sent a mechanic to inspect. The mechanic moved part of the shaft seal device back and forth (water coming in as he did so) and said, "You have to do this every once in a while. Sea weed/stuff gets in them and can cause a leak". No sea trial to make sure all was ok. Marina charged me 200.00 which I thought was wrong, but to not lose a repair resource.....I paid it.

Several more months go by before I used the boat again - which was the day after this past Thanksgiving.

Water pouring in on both shafts....significant flow. My impression is that the mechanic made things dramatically worse. Too, I am reluctant to accept that after the mechanic fooled with the seals, they would ...both....coincidentally......be leaking with a similar failure or flow rate due to random debris. The same amount of debris found its way into both sides and caused similar leaks?

I called the yard and the guy said pretty much the same thing....... lack of use can cause leaks.

My question is....................DOES LACK OF USE CAUSE THE SHAFT SEALS TO LEAK? Is the repair guy blowing smoke at me? I never heard of boat owners having to routinely or constantly fiddle with their dripless seals to keep them working.

Appreciate any thoughts and many thanks.
 
If you have a PSS shaft seal, these FAQ's may help. https://www.shaftseal.com/pss-faq.html#1

In general, the PSS seals work by having a stainless collar compressed against a carbon seal on a bellows. By now the face of the seal should have broken in. It's possible some foreign material has gotten caught between the collar and the rotor, but you should not be getting a lot of grass / seaweed in there. If so you may need to look at your strainer.

If the boat has been out of the water, you do need to "burp" the bellows to release any air in it, and ensure you are getting cooling water into it.

You didn't say at what speed the leak is occurring. Sometimes the collar is not compressing the bellows enough. When this happens, at a higher speed the bellows can move away from the collar. This opens up a gap and water can come in. Providing additional compression to the bellows would be the fix. Note: The set screws that fix the collar in place are single use. Don't reuse them, as the sharp point that grabs the shaft is dulled after the 1st use. A reused (dulled) set screw is not assured to hold the collar in place.
 
Basically what Brad said. Make sure there is adequate compression between the bellows and the seal face. If that doesn’t fix it you’ll need to check the seal faces themselves for nicks, scratches and such. Not uncommon to have to adjust after install.
 
I read about this problem all to often with PSS type seals. I bought my boat 11 years ago with the old style Tides Strong seals already installed. I have never touched them and 11 year later they have never leaked a drop. The PSS design would worry me and I would prefer a standard stuffing box instead.
 
I had these on my last boat for 20 years - no issues

shaft seals also require adequate water pressure from the raw water system.

thats the problem I just discovered with my new to me 450DA

Hope this helps

BEST !

RWS
 
I had new bellows installed as they were in excess of ten years old. The yard mechanic did not get them compressed enough initially and I had leaking issues. I compressed another 1/2 inch and been dry since. Fouling on the props causing vibration will cause the seals to leak as well. Bottom line is, all seal systems take some kind of service or attention at some interval.
Carpe Diem
 
We had dripless seals on the 370 SR Express and on the Tiara 3200. Both boats were pretty dry with no special maintenance performed.
 
Maybe A Dancer said:
I had these on my last boat for 20 years - no issues

shaft seals also require adequate water pressure from the raw water system.

thats the problem I just discovered with my new to me 450DA

Hope this helps

BEST !

RWS
Click to expand...


>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I visited with Ben Woody at the PYI booth at MIBS.

The information I posted above in red IS INCORRECT!

The water feed to the sealing surfaces DOES NOT build pressure.

It only serves as a cooling mechanism above a certain velocity moving forward, as seawater is pulled away from the seal.

PYI/PSS claims it is a GOOD PRACTICE to TEE two of these together from one engine to the other.

Leaks?

Check the boot for correct compression and or clean the surfaces with 600 wet sandpaper.

BEST !

RWS
 
Maybe A Dancer said:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I visited with Ben Woody at the PYI booth at MIBS.
Click to expand...
Funny, I met with Ben on Saturday because I need to replace my seals and my yard gave me a choice of replacing with Tides again or swapping over to the PYIs. Still haven't decided which to go with, but he said the bellows on the PYI's need to be replace every 5 years, so I'm not sure where the advantage is.
 
I put GFO packing in mine last year and don't expect them to need much attention.

Far simpler and these threads and some experience makes my wonder why?
 
Maybe A Dancer said:
I looked at the LASDROP at the show and was impressed with the idea they have an inner bearing surface that rides on the side of the prop shaft to improve stability

https://www.practical-sailor.com/sa...score-four-other-dripless-shaft-seal-makers-2

BEST !

RWS
Click to expand...
funny thing our company Glide Bearing and Shaft seals sells more shaft seals than all those combined.. we do around 15K units annually

I switched from Tides to Glide two years ago.. no issues, again they all make a good seal you need to make sure you have shafts aligned, engine aligned, solid motor mounts ( not old worm out ones) and yes water..

ours are used at Hi rpm in the wake/ski boat market they take a beating.. little to no issues
when a seal goes bad or gets destroyed you dont remove you side new one in place


https://www.glidebearings.com/marine
 
nealtrombley said:
funny thing our company Glide Bearing and Shaft seals sells more shaft seals than all those combined.. we do around 15K units annually

I switched from Tides to Glide two years ago.. no issues, again they all make a good seal you need to make sure you have shafts aligned, engine aligned, solid motor mounts ( not old worm out ones) and yes water..

ours are used at Hi rpm in the wake/ski boat market they take a beating.. little to no issues
when a seal goes bad or gets destroyed you dont remove you side new one in place


https://www.glidebearings.com/marine
Click to expand...
Cool. Now do it hanging upside down, under a v-drive. :)
 
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