My ABS started acting up last night, applying always at around 15mph down to like 5mph on dry pavement. I took apart the front end(replacing pads and rotors) and see where the sensors go into the hub assembly. I did some reading last night and don't think my problem is in the rear ABS due to my speedo working. Can I remove the sensors and clean them or check anything else with the rotors removed?? Are there any tests I can do? Thanks.