Had brake problem with my Ryobi ,so I did the shortening of the spring method,and it works.first take the top cover off,remove the circlip on brake drum,pull the brake back to release the drum and remove,remove the plastic cover to expose the end of spring,pull out the spring,remove the brake handle,push the brake spring up to reveal a coil spring,take the spring out and shorten it by 10mm and reassemble.good luck.
Tony d, July 2015