A pick-up head system for use with a surface cleaning vehicle comprises a housing with a debris receiving main inlet and a debris outlet. A rotatable door assembly is mounted on the housing at the debris receiving main inlet for rotation about a substantially horizontally oriented door pivot axis, for controlling the passage of debris through the debris receiving main inlet. In use, as the rotatable door assembly rotates about the horizontally oriented door pivot axis to thereby permit debris to enter the housing through the debris receiving main inlet. An air flow barrier disposed between the rotatable door assembly and the housing substantially precludes the passage of air and small debris between the rotatable door assembly and the housing.