I converted to rear discs on my scout ii and upgraded to the vet master cylinder. I have bled all the brakes and got it so fluid is coming, out but only have rear caliper engagement. My question is, I am not getting any front brake pressure, what could it be? my first thought is the combo valve so i watched it while Tom was operating the peddle and saw that little button going in and out. is it supposed to do that? I have the vavle off my other scout that I can try but dont know if its worth it since both were disk drum and the new set up is disc disc. any thought or advice would be greatly appreciated.