Hydraulic control circuit for a continuously variable transmission

A hydraulic circuit for a continuously variable transmission comprising a continuously variable ratio unit (“variator”) which is controllable by means of at least one hydraulic actuator acting on a movable torque transmission element of the variator, the actuator having opposed first and second working chambers and the circuit comprising first and second flow lines both connected to respective actuator working chambers for feeding fluid thereto and therefrom and means for supplying fluid flow through both of the flow lines, variable control valve means being incorporated in both flow lines for generating an adjustable back pressure therein and a further valve being connected between the two flow lines, upstream of the variable control valve means, whereby opening of the further valve enables flow of fluid from one flow line to the other in order to reduce pressure difference between the lines.