Hydraulic brake system

A hydraulic brake system comprising:

• a master cylinder with a brake pedal;
• a wheel cylinder;
• and
• a valve fluidly disposed between said master cylinder and said wheel cylinder,
• said valve including a valve bore having a first end wall opening and communicating with said master cylinder and a second end wall closed,
• said valve including a plunger slidably disposed in said valve bore and having a first end face opposed to said first end wall of aid valve bore and a second end face opposed to said second end wall of said valve to define therebetween a chamber within said valve bore,
• said valve including peripheral wall means interconnecting said first and second end walls to define said valve bore, said wall means being formed with a groove communicable with said wheel cylinder,
• said valve including means for permitting restricted fluid flow communication between said chamber and said groove,
• said valve including a spring biasing said plunger to a first position wherein said plunger covers said groove,
• said plunger having a first pressure acting bore on said first axial end face, which is subject to a first hydraulic fluid pressure from said master cylinder, and a second pressure acting area, on said second axial end face, which is subject to a second hydraulic fluid pressure within said chamber,
• said plunger being movable from said first position against said spring in response to a deference between said first pressure and said second pressure and to a second position wherein said plunger uncovers said groove to open fluid flow communication of said groove with said master cylinder.