BRAKE PRESSURE ADJUSTING DEVICE

PROBLEM TO BE SOLVED: To eliminate the need for various different arrangements of receiving holes by causing lip seals to hermetically abut the two pistons of a master brake cylinder. SOLUTION: A pair of lip seals 35, 36 receive a primary piston 43. In the other pair of lip seals 37, 38, the lip seals point in opposite directions, i.e., away from each other. The pair of lip seals 37, 38 receive a secondary piston 44. The two pistons 43, 44 are located coaxially in series and spaced apart by a compression coil spring 45. The four lip seals 35, 36, 37, 38 have the same outside diameter and different inside diameters to receive the pistons with different outside diameters. Thus, the pistons with general piston diameters can be used without the need to vary, e.g. the outside diameters of the lip seals and the diameters of receiving holes 34.