Patent ID: 7243767

Claim:
A hydraulic system ( 1 ) for an automatic transmission of a motor vehicle, the hydraulic system comprising primary and secondary pressure circuits (PK, SK) which can be loaded with hydraulic fluid from a pressure source ( 2 ) and in relation to a supply with hydraulic fluid of different areas of the transmission are differently prioritized, a pressure in each of the primary and the secondary pressure circuits (PK, SK) is adjustable, according to a system valve ( 4 ), and the secondary pressure circuit (SK) comprises at least one cooling device ( 8 ) for cooling the hydraulic fluid and a lubrication circuit ( 9 ) located downstream of the cooling device ( 8 ), between the cooling device ( 8 ) and the lubrication circuit ( 9 ), one bypass pipe (L 5 ), blockable via a valve unit (VE), is provided which can be controlled via the valve unit (VE) so that a hydraulic fluid flow rate (Q_K) supplied, via the cooling device ( 8 ), is adjustable without changing a hydraulic fluid flow rate (Q_S) to be supplied to the lubrication circuit ( 9 ).