there was a guy called " old used bear " that was a guru for auto parking brakes for rv's try googling him. I have read that there are brake shoes that wear out in the hub , but maybe I am thinking of something else. also google auto parking brake ....
after you google old used bear select : Oemys web Site j71 auto park
good luck and keep us informed
2016 Winnebago 35B v10
2006 Jeep Liberty 4x4
Blue ox Tow Bar