A hydraulic system for a multiple friction transmission, comprising: a first pressure relief valve 5 regulable by means of a first pilot pressure; a normally-open drain valve 8, which is a directional valve switchable between an open state and a closed state by means of a second pilot pressure; at least one first pressure regulator 11 for operating the drain valve by means of a first pilot pressure and a second pilot pressure, respectively; wherein in the event of detrimental hydraulic pressure build up, the second pilot pressure is dropped to open the drain valve, so as to relieve pressure through the drain line.
DRAIN VALVE
2018-03-22
Patent
Electronic Resource
English