Replacing a dripless shaft seal in the water.

[captmikem]

My “dripless” shaft seal was leaking pretty bad, so I ordered a new PSS shaft seal and installed it the past few days. 1.75 in shaft and 3 inch stern tube.

I was in the water so I had a couple extra pumps ready but the main bilge pump took care of the water without a problem. It took two evenings to replace it, only because I spent the first evening removing the shaft from the engine coupler. I have never had one this tight.

What surprised me was how poor of condition the bellows was in. You can see it was not leaking at the face but near the back of the bellows, and it was not a drip it was a stream. When I went to remove it the bellows pulled apart.

Just for general knowledge it was easy to replace in the water although the instructions are pretty adamant that it be done out of the water. I knew I had at least 8 inches I could pull the shaft aft so I was not worried. Some vessels you need to pull the prop to be able to move the shaft back far enough to remove and install the bellows.

All went well, very happy with the new one. (I pollished the inside of the coupler so I would have no problem inserting the shaft back in it). I just have to replace the vent line with a softer hose so it does not put any sideways force on the ceramic face.

M

 

[porman]

How old was that bellows? I think they tell you to replace it every 6 or 7 years.

 

[sunchaser]

Good job ?

My first PSS change was after 12 years. The parts that came out were in very good shape. The second set was changed after 8 years, again they looked good.

But, I’ve seen PSS or similar seals that looked bad after very few years with a variety of underlying causes. So to the OP, how old were the seals. If they leaked this bad after a brief few years, what would you guess as to cause?

 

[captmikem]

How old was that bellows? I think they tell you to replace it every 6 or 7 years.

Good job ��

My first PSS change was after 12 years. The parts that came out were in very good shape. The second set was changed after 8 years, again they looked good.

But, I’ve seen PSS or similar seals that looked bad after very few years with a variety of underlying causes. So to the OP, how old were the seals. If they leaked this bad after a brief few years, what would you guess as to cause?

I have had the boat three years so I do not know how old the seal was. I think it was just old and worn out.

I do not believe the original was a PYI as the bellows was thinner and not as "tough" as the PSS. Also the SS rotor had three bolts in it instead of the two set screws PYI uses.

Interestingly, it had a 3" hose going from the stern tube to a heavy bronze adaptor that brought it down to about two inches, which the belows was then attached.

I was 'always going to replace it' but had put it off until I had to.

 

[Puffin_NT32]

Regarding PYI's recommendation on replacing bellows every 6 years (maintenance kit), I replaced my original PSS bellows and seals last year, after 18 years and 2,400 hours. Seal was not leaking. In enclosed pics, left bellow is old (compressed from use), and the right bellows is the new. Biggest problem was pulling coupler from prop shaft (old school method, longer bolts and a socket).

 

[kthoennes]

This discussion and the photos of the spanky new bellows make me think I need to do more than just re-packing this spring. I planned to just replace the packing and the clamps but as long as I'm working on it anyway...

Mission creep, always mission creep.

 

[captmikem]

Regarding PYI's recommendation on replacing bellows every 6 years (maintenance kit), I replaced my original PSS bellows and seals last year, after 18 years and 2,400 hours. Seal was not leaking. In enclosed pics, left bellow is old (compressed from use), and the right bellows is the new. Biggest problem was pulling coupler from prop shaft (old school method, longer bolts and a socket).

Nice clean bilge! I used socket and long bolts to remove mine, but it was TIGHT! took me three hours and three different lengths of sockets.

Nice job.

M

 

[sunchaser]

Regarding PYI's recommendation on replacing bellows every 6 years (maintenance kit), I replaced my original PSS bellows and seals last year, after 18 years and 2,400 hours. Seal was not leaking. In enclosed pics, left bellow is old (compressed from use), and the right bellows is the new. Biggest problem was pulling coupler from prop shaft (old school method, longer bolts and a socket).

P
Your setup looks excellent. Might I suggest a shaft zinc added to engine side? Snug it up tight to SS ring as an added no movement device. Not uncommon to have slippage forward in this area if nuts are not installed correctly or things loosen up.