To prevent cavitation in a fluid circuit of a torque converter, without increasing pressure applicable to a torque converter clutch.

A torque converter includes an impeller shell and a backing plate defining at least a portion of a first hydraulic chamber, a cover and a piston plate defining at least a portion of a second hydraulic chamber, and a third hydraulic chamber. The third chamber is sealed from the first and second hydraulic chambers such that a hydraulic flow between the third chamber and the other chambers is at least restricted.