On March 31, 2003, about 1245 eastern standard time, a Cessna 190, N4413C, registered to Stag Park Flying Club, Inc., ground looped while turning off the runway after landing at Lakeland Linder Regional Airport, Lakeland, Florida, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airline transport-rated pilot and three passengers were not injured. The flight last departed Brunswick, Georgia, the same day, about 1100. The pilot stated Lakeland was his destination. He landed on runway 27 at Lakeland, and was not moving very fast when he started to turn left off the runway onto the closed runway. The airplane continued turning left and the right wing and right horizontal stabilizer went down and contacted the runway. The right brake became spongy and weak in the left turn and would not hold causing the continued left turn. The airplane came to rest facing north. The pilot further stated that he had not had any problems with the brakes recently and that there was no recent repairs to the brakes. He stated that when he taxied the airplane from the accident site to the repair hangar, the brakes operated normally. Examination of the accident site by NTSB and FAA showed a heavy tire mark on runway 27 from the left main tire of the airplane going to the southwest off the runway onto runway 23. As the airplane entered onto runway 23, heavy tire marks from the left and right main tires are visible up to the point the airplane ground looped and the right wing tip and right horizontal stabilizer tip contacted the runway. The airplane received substantial damage to the right wing tip, right horizontal stabilizer, and right main landing gear attach point. Testing of the wheel brakes at the accident site showed no evidence of failure or malfunction. The pilot then taxied the airplane to a repair facility. Further examination of the airplane by NTSB and FAA was conducted at the repair facility on April 1, 2003. Examination of the right main landing gear brake again showed no evidence of failure or malfunction. The pilot sent a letter to the NTSB and FAA from a mechanic at the repair facility, who subsequent to the accident disassembled the right wheel brake cylinder. The mechanic stated that the piston and the lock-o-seal tolerance was found excessive. The measurement should be .040 +/- .005. The actual measurement was .095. The piston bore was worn to the point the lock-o-seal completely went through the piston thus allowing fluid to bypass around the seal. An FAA maintenance inspector stated that he reviewed the letter from the mechanic involved and had a subsequent telephone conversation with him, The situation he describes in his letter does not fully cover all aspects of the problem. While some of the tolerances inside the master cylinder were out of specifications, this would not cause a total failure of the cylinder to operate. He stated that it would only bottom out (fail to apply brakes) about every 4th or 5th time while being operated on the bench, and would pump back up (apply pressure) the next pump. If it did indeed failed to pump up during the landing, it should have worked if applied again. At the time of the accident the wind was from 360 degrees at 10 knots.