a ring 57 with a thicker shoulder 95 an adjustment of the dead stroke of the secondary circuit of a tandem master cylinder may also be carried out the use of the pin 77 as an adjusting part is particularly advantageous as regards the adjustment of the dead stroke of the secondary circuit as a matter of fact said pin is arranged in a hole enabling it to be changed even after the complete assembly of a tandem master cylinder 23 after such a possible adjustment the control goes to step 137 and the manufacturing process according to the invention is terminated fig9 shows an advantageous embodiment of a manufacturing procedure of a master cylinder according to the present invention with a closed loop adjustment of the dead stroke value s the procedure as per fig9 differs from that shown in fig8 in that after steps 139 and 141 the control goes back to step 125 for a checking of all the alterations if the measured values are not suitable the loop may be gone through several times until the desired adjustment is reached or if none of the parts is fitting up to the rejection of a master cylinder which does not meet the requirements the selection of the adjusting parts at step 139 or 141 may either be a simple incremental one selection of the part exhibiting the smallest dead stroke difference compared with the previously tried part or it can result from more sophisticated strategies.