68 camaro proportioning valve (combination valve)HELP?

[72Z/28]

Hi Guys

I have new front 6 piston wilwood calipers, new wilwood floating calipers for the rear installed last weekend, and Wilwood master cylinder, which was installed by the previous owner. I recently replaced the old distribution block with a combination valve or proportioning valve similar to the photo attached below

http://s218.photobucket.com/user/72Z...nf9h.jpg.html][/URL]

I filled the master cylinder with brake fluid and disconnected the flexi lines to the calipers in order to flush the system (Gravity Method) . However, I realized that NO fluid was passing through the combination valve.

So I need your advise on this issue and what should be done to resolve it.

Thanks in advance