Brake control valve assembly for effecting increased rear braking action upon malfunction of the front system

A brake control valve assembly comprising a cylinder defined by a cylinder casing;

• a first pressurized brake fluid feed port formed in said cylinder casing for communication with a rear master cylinder;
• a first pressurized brake fluid discharge port in said cylinder casing for communication with at least one rear wheel cylinder;
• a piston having a rear end and a front end fitted within said cylinder, said piston being provided between its said ends with a head flange and a spring-receiving flange spaced from one another;
• a rear seal about said piston in the vicinity of said rear end;
• a spring between said spring-receiving flange and said rear seal;
• a seal valve interposed about said piston between said head flange and said spring-receiving flange;
• a carrying flange formed on said piston and spaced from said head flange of said piston towards its said front end;
• and a piston sleeve disposed loosely about and between said head flange and said carrying flange, said brake fluid feed port being in fluid communication with space within said cylinder casing between said front end of said piston and said carrying flange and said fluid discharge port being in fluid communication with space within said cylinder casing between said spring-receiving flange and said rear seal.