I just went through this same problem, four wheel drum MC. I bought some gasket material and cut it the size of the MC gasket hollowed out the center so the two cups can move up and down and placed it between the metal cap and gasket and the cover went on much tighter. It didn't leak so far but I haven't really tested it too long.
Being the breeze is power brakes without the recess for the rubber bushing to hold the pushrod, how do you use this MC with a manual brake car? Also, the ports on the newer MC are different sizes than the old one so how did you screw the brake lines into the newer Breeze MC?
Appears you didn't google my post. I stated that in a test fit I put the rod in, then tried to remove it to add the dust bellows and had to beat it out, destroying the new rubber bushing in the process, so it does secure that bushing well. The ports were definitely a different size than my 64 Valiant which had a single 1/4" tube from MC to distribution block. The 95-99 "cloud car" MC has dbl-flare 3/16" tube ports. An ABS has just 2 ports. Don't recall the tube nut sizes. I made my own tubes w/ adj proportioning valve on the rear tubing in case I later add front disks. Many MC's would work. Later ones have bubble-flare ports, but no problem since you can form those w/ a common dbl-flare tool (youtube), as I did just last week when replacing a brake tube on my 96 Voyager.
One reason I hate the OE master cylinders. If the cap leaks, it will not only remove paint but that means moisture can also get in to be absorbed and cause internal corrosion in your whole brake system. Other reasons are that cast iron is heavy and ugly when it rusts. A later 2-bolt aluminum MC is nicer.
