The classic way to create a bearing seal where none is was to slip over the axle a number of industrial "o" rings such that the one contacting the dust cap/ cup/body is sung enough on the axle to grip it well and of a large enough section to plug the gap between the axle and the dust cap/cup/body. Additional "O" rings butted up against this "sealing" one will keep the "sealing" one in place.


The best example of this is the Stein Zerk BB grease injection/seal kit. The same approach might also work with your pedal to keep the OEM seal in place. Andy.