Abstract: A rotary actuator includes one or more rotor vanes (40); an endplate (60); a corner seal (30) being positioned between the rotor vanes (40) and the endplate (60); a vane seal (20); a high pressure chamber and a low pressure chamber; and a single channel (22) extending from a lower portion of a vane seal groove (25) to a common channel (28) beneath the vane seal (20), wherein the high pressure chamber is in fluid communication with the corner seal (30) via the single channel (22) and the common channel (28). The common channel (28) may be formed in the rotor vane (40) or provided separately in a rotor vane flow sleeve (21) positioned along an interior surface of the rotor vane (40). The single channel (22) is machined from the bottom of the vane seal groove (25) to the area behind the corner seal (30).