Definitions for "Proportioning Valve"
Keywords:  lockup, hydraulic, brake, rear, valve
Regulates the hydraulic pressure in the rear brake system to prevent over-braking or lockup.
Hydraulic control designed to stop the rear wheels from locking up (rear wheels become "light" under heavy braking and therefore more likely to skid).
In a brake hydraulic system, a valve that limits the pressure reaching the rear brakes during hard stops to reduce or eliminate rear wheel lockup. Commonly incorporated into a combination valve (see).