No it is not necessary, I've changed many without doing that.. I go to NAPA and get a kit and crawl under and change.. They are in the backing plate for the brake on the inside of the dualls..Kit should have sensor with about 4' harness that just plugges into the harness on the chasiss..There'll be a round spring clip that you put into the hole before you install the sensor, take the old one out first, don't use it even tough it looks good.. Just follow the directions.. You need to run the coach, I think 10 mph to reboot the system to make the light go out.. Mike Mathews..