Uh, I think we're talking apples and oranges. Yes indeed there is a rear axle vent hose, but it has nothing to do with the brakes.
There are two front wheel brake hoses but only one rear. I know this rear hose is a bit on the expensive side, as it's only available (to my knowledge) from Thunderbird
parts houses, unless you can find a place that custom-builds them.
I rebuilt my entire brake line system several years ago. I don't recall anything special about removing/replacing that hose, and it seems to me I was able to reach it without crawling under the car -- just a wheel off.
I have a very strong suggestion: if your brake lines are original, replace them. One in particular -- the line that goes to the rear. It goes down from the
master cylinder, then makes a bend to run to the back. That bend has a little flat plate to protect it, but over the years it gets caked with mud and has a tendency to rot the brake line at that point. One day you hit the brakes and surprise! You can buy a complete set of stainless steel lines, highly recommended. Overall they're easy to replace; the only one that's a bit tough is the one that runs to the right front wheel. It runs along the firewall, and you have to thread it around a bunch of hoses and other fittings. Aside from that it's easy, and you'll be glad you did it. Replace all three hoses at the same time and you'll have peace of mind.
Bear in mind that when the hoses go bad, they don't necessarily let go. I guess they can, but the big thing to watch is swelling inside. You apply the brakes and then they're slow to release. Whichever, it's a good idea to completely rebuild the entire brake system on your 50-year-old car with a single
master cylinder.
