Abstract: A connection device for a brake fluid reservoir intended to link an outlet (10) of a brake fluid reservoir (1) to the supply inlet (20) of the primary circuit and to the supply inlet (21) of the secondary circuit of a master brake cylinder (2) or to two supply inlets (40, 41) of a manifold device (4) mounted on the said supply inlets of the master cylinder. A pipe system (3) has a main pipe (30) to which two branch pipes (31, 32) are connected. The main pipe (30) has an inlet end (33) connected to the outlet of the brake fluid reservoir and each branch pipe has a supply end (34, 35) that is connected to a supply inlet (20, 21) of the master cylinder or to an inlet (40, 41) of the manifold device (4).