Hydraulic control system for a wet dual clutch which comprises two clutches (4, 5) and is intended to be arranged, in a motor vehicle transmission, between an engine having a crankshaft and a gearbox comprising two coaxial input shafts (2, 3) extending along an axis X, the hydraulic control system comprising: - a casing intended to be fixed to the gearbox, the said casing comprising an internal tube extending axially about the axis X and creating an internal space intended for the passage of the two input shafts (2, 3) of the gearbox, the said casing further comprising a first and a second annular chamber (43, 44) which are concentric about the axis X, and positioned radially around the internal tube; the first annular chamber being situated radially on the outside of the second annular chamber; - a first and a second annular piston (45, 46) which are respectively mounted with the ability to slide axially inside the first and second annular chambers (43, 44) between a rest position and an active position; the first and second annular pistons (45, 46) each bearing a rotary thrust bearing (49, 50) intended respectively to collaborate with a first and a second force transmission member (25, 38); the first and second force transmission members (25, 38) respectively collaborating with each of the two clutches (4, 5) of the dual clutch so as to move the said clutch (4, 5) between a disengaged position and an engaged position; the rest position and the active position of the first and of the second annular piston (45, 46) respectively corresponding to a disengaged position and an engaged position of the respective clutch (4, 5); characterized in that the internal tube extends axially in the direction of the two clutches (4, 5) beyond the first and second annular chambers (43, 44) and exhibits at least one canal for the passage of a cooling fluid intended to lead the said cooling fluid towards the clutches (4, 5); the said canal for the passage of a cooling fluid exhibiting an outlet orifice opening axially beyond the rotary thrust bearing of the second annular piston whatever the position of the said second annular piston between its rest position and its active position. - a casing intended to be fixed to the gearbox, the said casing comprising an internal tube extending axially about the axis X and creating an internal space intended for the passage of the two input shafts (2, 3) of the gearbox, the said casing further comprising a first and a second annular chamber (43, 44) which are concentric about the axis X, and positioned radially around the internal tube; the first annular chamber being situated radially on the outside of the second annular chamber; - a first and a second annular piston (45, 46) which are respectively mounted with the ability to slide axially inside the first and second annular chambers (43, 44) between a rest position and an active position; the first and second annular pistons (45, 46) each bearing a rotary thrust bearing (49, 50) intended respectively to collaborate with a first and a second force transmission member (25, 38); the first and second force transmission members (25, 38) respectively collaborating with each of the two clutches (4, 5) of the dual clutch so as to move the said clutch (4, 5) between a disengaged position and an engaged position; the rest position and the active position of the first and of the second annular piston (45, 46) respectively corresponding to a disengaged position and an engaged position of the respective clutch (4, 5);