Originally Posted by johnnyquest37
I've had a PSS shaft seal on my boat going on eight years. I plan to do the six-year maintenance this coming fall. Never had a leak or any issues at all except one:
The shaft seal requires lubrication in the form of raw water. You'll see a hose fitting on the PSS shaft seal on the forward end. This allows a hose to be plumbed into your raw water system so that the shaft can get some raw water when the engine is turning the shaft. When the engine is not running, this hose can allow raw water to run the other way - from the shaft seal to the engine raw water system. Several years ago, I discovered sea water in my crankcase and finally figured out the water was coming from the shaft seal. Since then, I've raised the hose and installed a siphon break, but a check valve might work or even a regular valve that one closes when closing off the raw water thru-hull after shutting down the engine.
The instructions for installation have two configurations: for low speed boats, and for high speed boats. As much as we would like to think differently on race days, our sailboats are low speed boats. For high speed boats, the "T" off the engine is recommended so the water is not siphoned out of the bellows during high speed. For low speed boats, there are no connections to the raw water system for the engine, only a hose that connects to the bellows. This hose is filled with raw water by gravity up to the waterline of the boat. I installed a clear tube so I can see the water level. I "burped" the bellows after splashing the boat and the water level has remained there since.
Instructions here: PSS Shaft Seal