The invention is directed to an apparatus for cleaning the bottom and sides of a water-filled pool with an automatic pool cleaner equipped with motor-driven track belts (9a, 9b) and with a poolside programming module to control the cleaning method. The pool cleaner is equipped with two counter-rotating brush rollers (14a, 14b). Each brush roller is provided with a longitudinal shield (17a, 17b) which partly encloses the brush roller and is sealed against the pool cleaner chassis (1) to increase the water velocity generated by the pool cleaner pump impeller (4) thereby increasing the suction developed between the pool cleaner suction box (8) and the pool bottom or side walls, as applicable, to achieve more efficient cleaning and to ensure the travel of the pool cleaner, particularly along the side walls of the pool.