The Charge of the oil force from the lock-up clutch is completed by means of two valves: the relay valve and the signal valve. In such a arrangement the sign valve controls the force on just one aspect of the relay valve, which controls the strain within the lock-up clutch. https://hectoruabzy.blogerus.com/56399541/helping-the-others-realize-the-advantages-of-torque-converter-clutch