I push as much seal as I can into the bottom of the cap first making sure it is deeply seated in the groove. Then slowly work your way out of the cap one side at time using a heavy pipe or socket. When I know its really seated, I very carefully pull it out and install it into the block. With the crank in place, this is the only way to know for sure you have enough seal forced into the block groove. Do not cut the ends till you set the crank back down and pound it into the seal with a rubber hammer. Leave 1/8" or so of the seal sticking out and taper the ends with your fingers so the don't spread out. Do the same using the cap again, only this time compress the seal as go. Think of it as a spring being compressed. Leave the ends a little proud of the cap and add a little sealer to the steel matting surfaces on the cap and block but not the seal. The seal will now try to uncompress forcing itself together at the joints.
Back when the material was better, you would actually pack the rope into the block groove with a special tool and hammer. As the crank rotated, the seal would work itself back to a relaxed state spreading the force out around the whole seal.
When done right, the crank will be hard to start rotating, but spin fairly easy once broke free. You should feel resistance, if not, its not tighten.
Joe
