If the PSS Shaft Seal's Rotor is removed and re-installed, PYI suggests that you replace the O-rings within the rotor. If the Rotor's set screws are ever removed, they should also be replaced as they are designed for one-time use. This is a replacement kit for the o-rings and set screws.
Here's what comes included with all PSS O-Ring Kits.
Be sure never to use the same set screw on the shaft twice. There are two set screws in each of the two holes in the stainless steel rotor. One is tightened onto the shaft, and the other is tightened onto the first lock in place against the shaft. The set screws are made with a cup at the base that compresses into the shaft, ensuring a secure grip.