The load sensing and proportioning by-pass valve is a device incorporated into the brake system that senses the amount of weight the vehicle is holding and adjusts the brake fluid pressure to compensate for this additional load. Located above the rear axle assembly, it consists of a valve, spring shaft, and adjusting bolt. When bleeding the brake system, it is necessary to bleed the load sensing proportioning and by-pass valve last, after all the wheel cylinders and calipers are bled. In the event of poor braking performance, have the system adjusted by a dealer service department. If it becomes necessary to remove the assembly for replacement of another component, be sure to mark the position of the adjusting nut, as it must be installed in exactly the same position as before removal.