My brake proportioning valve is leaking like a siv on my 4kcsq. I have little to no pedal pressure and I have to push it to the floor to stop. I fill the master cylinder once a day. Anyone ever had this problem? Is it easy to replace? Where can I get one for cheap $$$? Any help is appreciated! Thanks, Craig Porter 86 4kcsq 2.5 cat back Borla, Eibachs 70 914, 911 conversions