The tire shop where I got the brakes fixed on a 93 Cherokee said the "base pressure" is so high it blew the vacuum hose off the master cylinder. Haynes manuals and Mopar websites don't list such a thing. Is "base pressure" another name for manifold pressure or vacuum pressure or what?

Maybe there's more than one "base pressure" but I had a problem with another model car (MB) and the base pressure was the fuel pressure. (I truly don't know what that means, not did I ask nor would I probably have understood.)

There is also a base pressure with standard transmissions - but, again, what that means is unknown to me.