Adjustable Brake Proportioning ValveThis valve is typically used to decrease the pressure to the rear brakes. When converting to a dual master or disc brakes the rear drums require less pressure and this valve is put in the front to rear brake line to reduce the pressure to the rear brakes. It can also be used in the front brake lines to reduce pressure. Pressure adjustments range 110 1200 PSI and provide for a maximum decrease of 60% in line pressure. This adjustment lets you fine tune