What to do about a leaky brake booster

[My_favorite_Brougham]

Well I was poking around the area, test driving old Cadillacs because that's what I like to do in my spare time. And I found an '87 Brougham that I might like to pick up, but... I am told by more than one local mechanic that the brake booster (or vaccuum booster) has a leak and needs replacing. He quotes $400 plus more labor and other problems. This is beacuse it's probably just a seal, but because they dont make replacement seals, he has to replace the WHOLE thing. My question is what can I do about the vaccuum booster? Innerauto.com has multiple brake boosters in the neighborhood of $80-$175, depending on the vaccum switch and the master cylinder. These numbers sound a little bit more likeable than 400+. Can I simply replace it myself, like I did the radiator on my '90? Can I get one from the junkyard?

[Night Wolf]

You can replace nearly anything yourself if you have the tools, time and skill.

I would just replace it myself.... shoudln't be too hard... or too expensive.

Odd that it went tho... kind of a rare thing to go.

[Motorboat]

The booster has an internal diaphram which is made of rubber which constanly maintains vacumn pressure in the can. As stated, it rare that this rubber fails however, if any of the metal parts develop leaks due to rust the vacumn is lost. Suspect areas of this are where the master bolts to the booster and mounting hardware of the booster itself.

An easy way to determine if the booster is bad is to pull the vacumn hose off of the booster and if you feel air pressure or hear a whooshing noise either the bladder or the check valve is bad. Both of which are replacable. Easy fix is to replace the entire unit from a doner vehicle. These boosters and masters are not Cadillac specific.

[The Ape Man]

There were a few years where booster failures were pretty common on RWD Cadillacs. '79 was one. They are easy to replace if you own a 3/8 drive universal. Get one with the same vacuum switch on it if it's there. Hang the master cylinder up with tie wire instead of cracking the hydraulic lines apart.