[villagetinker]

They might be out of adjustment. Ours have an automatic adjuster which activates when the cart is backed up and the brakes applied, like the old style drum brakes on cars. There might be a build up of dust or the brakes may be glazed, and as you asked they might be worn out. On all of the carts i have looked at, removing the lug nuts and the wheel will give access to the brake drum, which can easily be removed. NOTE: the cart is on a LEVEL surface, and the front wheels are blocked and the brake is off, and key removed. I do not remember if the brake pads were riveted or bonded, but i was just looking at some new ones and the pad was about 3/16 inch thick, if you are down to 1/16 or less consider replacing. There are several vendors that will do this at your house, I used Todd Casey a couple of times.