On May 9, 1993, at about 1020 hours Pacific daylight time, a Cessna 195, N2171C, ran off the runway during the landing roll and collided with a tree at Swansboro Airport, Placerville, California. The pilot was completing a local area visual flight rules personal flight. The airplane, owned and operated by the pilot, sustained substantial damage. The certificated airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at Swansboro Airport at about 0812 hours. The pilot stated in the pilot/operator report that he entered the Swansboro Airport traffic pattern to land on runway 090. He said that the initial rollout was normal, and then "a slight turn to the right was corrected for...then rudder and finally brake was applied to stop the movement to the left...it was then apparent full rudder, brake and up elevator was not working." The aircraft left the runway as he applied full braking. The left wing struck a pine tree which spun the aircraft into more brush, trees, and a dirt bank which runs parallel to the runway. The pilot said he suspected a weak right brake because of the leaking wheel cylinder and the fluid found on the brake after the accident. In the written pilot/operator report, the pilot said the right side main landing gear collapsed and that the gear box area was "badly damaged." The airplane was examined by an aircraft mechanic with airplane and powerplant ratings under the guidance of the Federal Aviation Administration on June 15, 1993. The mechanic told Safety Board investigators in a telephone conversation on June 17, 1993, that after examining the airplane, the left brake appeared to be operational. The brake pucks were in good condition and the brake housing was free and moved back and forth. He reported that the left brake appeared "good and hard" when he pushed on the brake pedal. The mechanic reported that the right brake housing "looked good." The right brake line was broken from impact damage. The mechanic did not find any fluid leaking from the wheel cylinder. The mechanic told Safety Board investigators that he "suspected the lock O ring seal had gone bad in the master cylinder." The mechanic was unable to disassemble the master cylinder.