My rear wheel (brake side) bearing has stopped spinning smoothly only a few weeks after having installed it correctly. This problem has occurred twice now. The rubber seals seem to be in good shape and I have made sure the bearings are well greased before riding. I have been using brake cleaner to clean my wheel hub and bearings... Is using brake cleaner okay on bearings? Is there something better? Should I be removing the bearing seal and cleaning/greasing the inside often?