brakes leaking from proportioning control valve

[Kisner]

The 3" brass cylinder is your proportioning valve. The other part (where the master cylinder and proportioning valve hook into) is your brake fluid distribution box and brake warning switch. Technically, I believe it's called a pressure differential valve. Believe you can get 1 or both from Mustangs Unlimited or National Parts Depot. If not, you might be able to get an original used one from Metro Mustang. Not sure where the leak could be coming from other than a bad flared end on one of the lines or possibly loose connection. If they're a hair loose, I know from experience fluid will run out. Can you see fluid running out when someone else presses the brakes down? Also, is any fluid coming out of the brake warning switch? I believe there's 3 rubber seals in the fluid distribution box. If one's gone bad, I'm not sure, but it could be forcing fluid out the connection.