I have a leak in my 99 deville rear break line. I am going to swap the lines and hoses on both sides out. When pulling out the old lines, I noticed what is pictured. There is one for each wheel. What I really want to know is what are they and can I reuse them or do I have to swap them out when I change the lines. Of course I will reuse them provided I can get them disconnected. Any help would be appreciated.

 

I asked the dealer. It is a proportioning valve and they can be reused. There are two; one just underneath the frame and forward of the rear driver side wheel and one underneath the rear of the car just inside the passenger side rear wheel.

 

proportional valves are used in cars that have front disk brakes and rear drums. the function is to apply different pressures to the brakes, more to the disk brakes and less to the drum brakes.

they can be reused but often they fail by corrosion due to moisture in the brake lines. regardless of recommendations, one should flush the brake system when new brakes are installed. new fluid will be moisture free.