I have a 1981 Chevrolet C30 car carrier with an LS 6.0L. The front brake line coming out of the master cylinder to the combination valve was replaced. Both front bleeder screws were stripped so both front calipers were replaced. LH front bleeds no problem, RH front won't bleed. I've pressed the "button" on the combination valve and tried to pull the fluid with a vacuum hand pump with no success. The rear bleeds fine. I'm assuming the master cylinder doesn't need to be bled because the LH front is getting fluid without a problem ? Any help would be greatly appreciated!