What are proportioning valve?

Proportioning valves are hydraulic components used in automotive brake systems to regulate the pressure applied to the rear brakes relative to the front brakes. Their primary function is to prevent rear wheel lockup during hard braking, which can lead to loss of control. By adjusting the brake force distribution between the front and rear wheels based on factors such as vehicle weight and load conditions, proportioning valves help maintain stability and improve overall braking performance. These valves can be either mechanical or electronic, depending on the vehicle's design.