Abstract: A filter media supply and extraction apparatus for a plate type liquid filtering device having a stack of separable filter plates. The extraction mechanism comprises a driven roller for each sheet of filter media in combination with an adjacent, movable bar having a series of spaced apart pinch wheels mounted thereon for penetrating accumulated cake and filtered dirt on the media when an actuator moves them against the roller as the media is being advanced. The driven rollers are mounted on separate bearing plates which are movable in response to sensor signals to steer the moving filter media and maintain its alignment with the filter plates. The supply section of the apparatus comprises a series of supports for supply rolls of filter media provided with adjustable centering means to help maintain proper alignment of the filter media between filter plates.