Abstract: A tamper resistant spring brake actuator with a stroke position indicator has a cover attached to a flange case by a removable clamp, with a head permanently attached to the flange case by a one-piece continuous clamp member, which is permanently deformed in place during assembly. The cover, flange case and head have annular rims, which are relatively flat and smooth. The one-piece continuous clamp ring is in contact with and clamps the outer flanges of the flange case, the parking chamber diaphragm and the head. The stroke position indicator can be treated with a surface protector to minimize the accumulation of oil and road debris.