| abstract |
A first clutch circuit for an automatic transmission in a hybrid drive vehicle comprises an apply line extending from a manual valve to a clutch, with a check ball disposed in the apply line operable to move out of the apply line upon upstream fluid pressure, and an exhaust line extending from the apply line, downstream of the check ball, to an exhaust valve. A driver-triggered valve actuating means operates to close the exhaust valve when the driver selects drive with a driver shift lever and to open the exhaust valve when the driver shifts out of drive thereby releasing the clutch. |