have a miprom 21 ac car with the disc brake. have a strange problem, the car will take a call, lift the brake and then just kind of hover at the floor, it may move a little each way, it will do this for 3-5 seconds, and then take off to the next floor, as it comes into level, it will do the same thing, slow down, hover, like it is looking for floor level, dzu and dzd come in, and it will kind of hover slightly back and forth, not more then an 1/4 inch or so, and then finally set the brake at that point it is about an inch or so low on all the floors, I'm thinking that maybe the car is trying to find the learned floor level, maybe position encoder is failing, although it will run full hi speed runs and not fault out , just does the above scenario. thinking of doing a learn run to see if that helps, but thinking about the encoder. any ideas