Put disc brakes on the front of my 37 Buick and need to remove the master cylinder flare seat from the line to the front calipers. Dual master is a drum/drum one so both seats have built in 10# residual pressure valves so have to replace the front one with a 2# valve either in the seat or an inline one. Thinking of using a small tap in the seat hole to pull on if seats aren't in really tight. Any advice? Thanks. If necessary will get another MC even thought present one is brand new.