Vacuum brake booster having tubes through which attachment screws pass and method for realizing same

A method for making a vacuum brake booster whose housing is crossed by tubes for the passage of screws for attachment of the brake booster to a partition of a vehicle passenger compartment, the method comprising:

• making a peripheral groove in a front portion of each tube, wherein a rear extremity of each tube is configured so that the rear extremity is crimpable to the back of the housing, wherein the housing is formed by the back and a cover;
• attaching each tube to the back of the housing by crimping its rear extremity in an opening in the back of the housing, wherein near a threaded front extremity, at a through-hole in the cover, each tube crosses the cover to accommodate, on the exterior, a lug of a master cylinder;
• installing, after having crimped the rear extremity of each tube in the back, an intermediary piston on the tubes, therein delimiting two chambers in the housing;
• installing a flange including a ring, a sleeve, and a lip on the front extremity of each tube;
• pushing each flange so as to engage the sleeve and the lip in the peripheral groove and crimp each flange to its respective tube, wherein the crimping of each flange leaves a wedge-shaped free space configured to accommodate a gasket between each flange and its respective tube;
• inserting a gasket between each flange, its respective tube, and the cover;
• installing the cover and attaching it to the back by securing a membrane of the piston in a crimp region between the back and the cover;
• and
• securing the cover between the lug of the master cylinder and the ring of the flange by a nut screwed to the threaded front extremity of each tube.