Reply to "vacuum assisted brakes"

The Pantera unit is very similar to the American Bendix unit.

It is crimped together. There is nothing servicable on it from the outside.
It needs to be disassembled to do that.

That big grommet that you see through the push rod port is actually part of the big rubber diaphram. At least it is in the Bendix unit.

They can be disassemble without damaging the case but you need a special jig to hold it and a hydraulic press with an adapter for it.

Harmon Brakes in California does them. Gets about $150 to do it.

He has all of the jigs and parts for them.

There is another unit used here on Fords called the Midland.

It is disassemblable with a large removable clamp on the exterior.

I just did one of those and screwed it up. Some of the internals are made out of bakelite. It is fragile and brakes very easily.

Nothing for a bull in a china shop should attempt. Those parts are no longer available from anyone.