Google has failed me. Cardone's tech manuals are non-existant, so I remembered (I know...I'm slow) Somebody at the H.A.M.B knows the answer... I've been working on my '48 F1 for a couple years now. Getting closer to street deployment, but I'm still a ways off. As with everything else on this re-build I've had to replace the master cylinder. I have 4 projects I'm working on at the same time (1949 Ford Tudor Sedan, 1956 Chevy 210 two door post and a 1966 Ford Fairlane 500 XL 2 door), so I'm always working with a shoe-string budget. Instead of going disc brakes out of the box I just opted to go stock for now. I order the replacement Cardone brand M. Cylinder (p/n 13-21050). When it came in the first thing I noticed was that the cap was different in that it had both a large and small cover. See image. Pulling the small cap I see what appears to be a metal sleeve at the bottom. Trying to unscrew the bottom,, larger cap I put so much effort into it that I thought something would break. Before I get my 4' cheaper pipe on this thing, have anyone else seen one like this? Thanks in advance.