Abstract: An improved third accumulator check valve is provided for the valve chamber which services feed oil to the release side of the intermediate servo cylinder of a turbohydramatic transmission system for motor vehicles wherein the intermediate band is released as direct clutches are applied. It comprises a positive seating valve in the chamber exhaust port, preventing exhaust port leakage which results in premature band application and clutch drag, and is characterized by a valve body which has more favorably disposed outer lift surfaces and an internal bore flow chamber with additional lift surfaces, said bore being provided further with a flow-released bore closure biasing the valve responsive to active flow pressure with assisted force into a continuously seated position.