A system, apparatus and method for controlling the height of a frame of a self-propelled high ground clearance, agricultural product applicator above a ground surface utilize a trailing link suspension system including an extensible air strut, for connecting ground engaging wheels of the applicator to the frame of the applicator. The trailing arm suspension system includes an upper suspension arm attached to the frame, a lower suspension arm providing sole support of a ground engaging wheel attached to the lower arm, and the extensible air strut interconnected between the upper and lower arms. Height of the applicator above the ground surface is controlled by regulating a flow of pressurized air to the air strut, to thereby control extension of the air strut.