<p>A de-aeration hydraulic circuit having application in a hydromechanical transmissions utilizes a hydraulic fluid reservoir to de-aerate hydraulic fluid. The circuit includes a high pressure side and a low pressure side having a bleed down valve therebetween, the opening of the bleed down valve causing fluid to flow from the high pressure side to the low pressure side and through a valve to the hydraulic fluid reservoir where the pressure drop causes gas that is entrained in the fluid to bubble out and vent from the atmospheric reservoir.</p>