HELP my cart is possessed................We just started our vacation and something is bad wrong with brakes?......... 03 IQ ds......occasionally when applying the brakes it seems the rear tires momentarily lock up, the brake pedal jumps up and hits your foot........Other times brakes feel normal...............I did try to adjust by going backwards and slamming on brakes, and that seemed to help but only temporarily..........It does not seem to matter if you brake easy or hard, or how fast you are going.......Please any advice would be appreciated...............hparm