Brakes

ok boys IM an old school wrench,I have a 73 type 1 v.w. I have been trying to get a brake pedal with poor results 2 masters the rears are adjusted properly & the L/rear brake hose has been replaced ( it was budging) Im using a mighty vac and even & 22 inchs vacumn I get little results,do you think this could be a residual check valve problem in the master even though by the looks of the adjusting rod its never been touched,when I crack the fitting at the master the vacumn goes away…god I hate V.W.s