Prepare your semi to be Ready for the Road Ahead , with the Thermaflow 9.2" x 20" x 22" 30 gpm Hydraulic Cooler Assembly that provides enhanced hydraulic oil cooling. Thanks to its series of fans that cool the hot oil, this replacement assembly is the ideal option to improve overall hydraulic system performance. Designed with a directional control valve to provide easy rotation changes or drive selection. FleetPride is your First Click in Heavy Duty .