Patent ID: 8667793

Claim:
Brake fluid reservoir combined with a tandem master cylinder, comprising: a gauging well, that is fluid-tight at least in a movement range of a float installed in the well for monitoring the brake fluid level in the reservoir and for generating a signal, the reservoir being formed of two parts, an upper part and a lower part, each of the parts being provided with partitions and well elements which, when the two parts are assembled, form compartments and the gauging well, the two parts each being made of a thermoweldable plastic so that they can be assembled with one another by thermowelding walls of the two parts and partitions that compartmentalize the reservoir, by pressing together edges that have been melted beforehand, characterized in that the walls ( 111 , 121 ) and the partitions ( 112 , 122 ) are assembled by thermowelding the edges together with the exception of the edges ( 113 a , 123 a ) of the well elements ( 113 , 123 ), and that the edge ( 113 a ) of the upper element ( 113 ) or the edge ( 123 a ) of the lower element ( 123 ) of the well ( 104 ) comprises a lip ( 116 ) and the edge of the other element ( 123 , 113 ) of the well has a guide surface ( 123 a ) collaborating with the lip ( 116 ), the compression of the lip ( 116 ) achieving fluid-tight contact with the guide surface ( 123 a ), deformation of the lip toward the exterior of the gauging well ( 104 ) achieving a fluid-tight joint between the edges of the two well elements, without generating any projections toward the interior of the well produced by the assembly under the pressure exerted by the bringing-together and welding of the walls ( 111 , 121 ) of the reservoir ( 100 ).