Master cylinder for a braking system

A master cylinder, comprising:

• at least one chamber delimited by a piston, the chamber being connected to the brake circuit and supplied from a brake fluid reservoir installed on top of the master cylinder by an end fitting on a bottom of the reservoir engaged in a nozzle on a top of the master cylinder body, wherein the piston has a nose of reduced cross-section, upstream of a skirt of the piston, guided in a bore hole of the master cylinder, and wherein the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position and straddling at least partly the nose;
• and
• a valve module situated in the drill hole and configured to manage communication between the reservoir and the chamber as a function of the position of the piston and a pressure in the chamber with respect to a pressure in the reservoir, wherein the valve module includes:
• a cylindrical body configured to be situated led in the master cylinder drill hole, the cylindrical body provided, on a reservoir side, with a valve seat, on a chamber side, with a travel limit stop, and accommodating a float valve movable between the sealing seat and the stop, the float valve projecting beyond the stop to come into contact with the piston;
• wherein the float valve includes:
• a check mechanism connected to a cam coming into contact with the nose or the skirt of the piston, the check mechanism cooperating with the valve seat, the cam being retained in a housing of the valve module;
• and
• an elastic connector between the check mechanism and the cam configured to enable an elastic compression of the check mechanism by pressure applied, from an expanded state of the elastic connector.