Brake Booster Disassembly

[Captain Obvious]

My brake booster stopped boosting last night. Kind of a surprise, but thankfully no brown.

I took the booster off my car and I would like to open it up to have a peek inside. I've tried a couple methods to get that sucker open but have been unsuccessful so far.

I know several of you guys have succeeded in getting the booster open, but I couldn't find pics of any of the rigs used to accomplish that feat of strength. Has anyone got any pics of what they used to hold and twist?

[Zed Head]

"No brown"?  Euphemism?

You need a special tool, I think.

[cbuczesk]

It takes some effort to unscrew it. I think I used a couple of breaker bars.

Chuck

 

[240260280z]

drilling a 2X4 to make a lever and a big vice to hold it helps.

 

Caveman mode for that one.....

[Freez74]

If you can get it apart, where can you find parts to rebuild it?  Mine stopped working, too.

[Namerow]

Some time ago, Blue posted a nicely-illustrated piece on rebuilding a MasterVac unit.  However, I think it was on the Atlantic Z Club site (nla?).  Maybe he can re-post it hear.  IIRC, his problem was a ruptured diaphragm... which he repaired using some kind of sealant.  As for me, I decided to just buy a rebuilt unit from NAPA.  It wasn't that expensive and it spared me the grief of taking the old unit apart.

[Patcon]

I have some pictures of the tool we built. Some 2x4's and some plywood. I will try to find them...

[Freez74]

I just checked Rock Auto, and they are still out of stock for a 74.  I'll check NAPA.

[madkaw]

There are still places that rebuild these units . I recently had a 72 rebuilt .  

 

http://brakematerialsandparts.webs.com/boosterrebuilding.htm

[Dave WM]

on mine it turned out to be a seal on the piston. Did not have to take apart to get it, I prob could have fixed it but by then I had already gotten a replacement and installed it. Does it leak at all?

[Captain Obvious]

Thanks guys. Hope someone comes up with a couple pics. I know there was/is a special tool recommended for the job, but I'm looking for homemade cheap caveman options. And I saw some references to pics on Blue's site, but unfortunately the site is still dead. Here's to hoping that wonderful reference source comes back soon.

My unsuccessful attempt was to bolt the booster back to the firewall (to hold one side of the shell) and then try to turn the other side using a two foot long bar I made out of angle iron which I had drilled for two of the mounting bolts and the center plunger. Fit great, but the angle iron couldn't take the force and started to buckle. The case didn't budge.

I'm not sure what I'm going to find when (if?) I get it open. All I know at this point is that the main diaphragm is intact at this point. The booster holds vacuum, but doesn't boost. I theorize that the valve is gunked up with crud due to drinking brake fluid from a master cylinder failure that occurred before my ownership.

I figure the worst that happens is that I tear the diaphragm splitting the case and I'll have to replace it with remanufactured sooner rather than later. I'd like to nurse this one along until the off-season and do a more permanent replacement then. I'm hoping that if it's just a clogged valve, maybe I can clean it out and continue to use this one until I take the car down for the winter.

I'm thinking that even if I tear the diaphragm, it'll still be a suitable core, so no loss there. And besides... I've never been inside one before and it would be a learning experience.

[sweatybetty]

CO, i have a few pics on my re-build thread, they may help a bit. i used a pair of vise grips on the "v" shaped part of the outer flange that holds the case halves together. clamp them on there tight, then use a large crescent wrench to turn the vise grips. this basically will open the "v" up and allow you to separate the 2 halves.