1990-92 STEERING Audi – Power Rack & Pinion 80, 90, 100, 200 1992 80, 100 DESCRIPTION & OPERATION Steering system consists of a belt-driven vane or rotary piston hydraulic pump, rotary piston pinion gear assembly and an oil reservoir. The flow control valve supplies fluid to the proper side of the rack piston when the steering wheel is turned. The pump mounts on the front of the engine. Two different rack designs are used. The 80 and 90 models utilize a rack assembly that extends the rack from one side of the housing. The steering links are attached to a bracket on end of rack. The 100 and 200 models use a rack assembly that is supported at both ends. The steering link bracket is attached to the center portion of the rack, through a window that exposes the rack. Rubber boots protect exposed portions of the rack from dust and contamination.