I’ve been on vacation and I haven’t had any time to work on the car. However, I have been doing lots of research and ordering things. This of course causes a debate with my son when I try to get him off the iPad. He just doesn't see the difference between "research" and playing games.
Everything in the SL-C is low and the brake master cylinders are no exception. They are mounted below the brake calipers and gravity will cause brake fluid from the calipers to drain back into the master cylinder which causes excessive caliper piston retraction which results in a longer brake pedal stroke. To solve this problem, a residual pressure valve (RPV) is installed. A 2 psi RPV is firm enough to prevent fluid from flowing back but not so firm as to extend the caliper piston which would cause the brakes to drag. Since there are two master cylinders (front and rear) two valves are needed. The kit came with valves, but some builders have had issues with them leaking so I upgraded them to Wilwoods.