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You are correct on just needing to pull the shaft out far enought to get the PSS shaft seal parts on over the shaft end. Be careful about removing all burrs on the shaft or you will damage the "o" rings on the stainlees steel rotor when you put it on.
My 2 cents....
I have had a PSS shaft seal on my sail boat with a perkins 4-107 for the last few years. The perkins shakes quite a bit at a cold idle and it has never caused the shaft seal to leak a drop. Normally it does not leak at all, and does allow a very dry bilge.
Originally the yard installed the shaft seal vent hose to a "T" in the raw water cooling line. This worked fine until the next time I changed the impeller and the water kept comming out of the raw water pump with the engine thru hull closed.
So next I ran the shaft seal vent line above the water line, and removed the "T". My boat does not go over 8 knots, but the shaft seal made a high pitched squeal that means the seal is not getting water. It also got rather warm. Burping the seal did not help.
Called the company and they confirmed that raw water cooling should be connected to the vent line if the design of the boat might cause a suction in the shaft log. A valve should be installed in the vent line and used to close the vent line when you want to change your impeller, and to regulate the pressure to the shaft seal vent line. The pressure should not be so high as to cause the shaft seal to leak or the bellows to deform. 4-6 psi is about right for mine. You also need to get the hose angle right so there is not to much (or any) side pressure on the vent hose barb or it will pull the seal out of alignment and it will wobble, but still it will not leak.
The seal is not totally maintenance free, but pretty close and the PSS had not been an issue since I had reinstalled the pressure raw water line. Until last week when I was out sailing and heard a metal on metal bang, bang, bang noise coming from what sounded like the shaft area. (My shaft spins while sailing and cannot be locked in gear.) The bellows and the carbon side of the PSS shaft seal was wobbling so hard back and forth as to make the banging sound. This was the first time I saw the PSS spray water into the boat. This was not a large volume of water, as it only sprayed as it banged against the shaft, but it was enough to "stop and fix it now". So I stopped sailing, realigned the PSS by hand and the water stopped. Then I limped back to the dock at under 2kts so the shaft would not spin and called the company.
They said that I must have got something stuck between the faces of the seal and to take 600 grit sand paper and go around both faces 30 times.
Did that and the seal stopped banging and spun correctly. 600 grit sand paper has now been added to the boat stores, as I would have rather done the sand paper refacing at sea when the problem happened.
While I had them on the phone I asked what the life of these seals were under recreational use. They told me to change the bellows every 6 years and I should get 20,000 hours out of the seal.
I have one, I'd get another, but I can understand why some people do not like them, as they may not be correct for every boat.
"Ubi libertas habitat ibi nostra patria est"
Last edited by Grumpymx; 04-19-2009 at 11:41 PM.