Am having trouble with a 65 Vert with front disk brakes. Has a 2 lb residual valve (new) installed on the front brake output of the MC. MC is new. Pedel goes to the floor on initial braking then solid pedel after that. Brakes have been bled repeatedly-no air. I think it's the MC but no one agrees since it gives a good pedel after 1 pump. Brakes were fine before being switched to disk. The drum brakes were shot so we upgraded. Any thoughts?