• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Replacement brake boost

daddycreswell

Contributor
Bronco Guru
Joined
Jul 30, 2011
Messages
2,744
Loc.
Lebanon, TN
A member graciously gave me a brake booster setup. He mentioned that he booster could be bad. How do I check it, and how do I find a replacement? I don't see any identifying numbers on it unless it's hidden where it mounts to the mount.
deb6dcb301a9e51df9cf7e663131a51c.jpg


Sent from my SM-S901U using Tapatalk
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,645
Get yourself a standard check valve for that booster, whether a new one from the store, or an old one from an old booster you might have.
Pop it in the rubber grommet hole and apply some vacuum to it from a running engine.
Unless you happen to have a vacuum pump handy?

Optimally it be nice to have a shut off valve in the hose so you can isolate any vacuum leaking to the main diaphragm and not a faulty check valve.
If it loses vacuum, it needs to be rebuilt.
If not, press the pedal rod on the back of the booster and see if the poppet valve opens.
You should hear the vacuum release.

I didn’t ever done it, but that seems like it would work.
 
OP
OP
daddycreswell

daddycreswell

Contributor
Bronco Guru
Joined
Jul 30, 2011
Messages
2,744
Loc.
Lebanon, TN
Get yourself a standard check valve for that booster, whether a new one from the store, or an old one from an old booster you might have.
Pop it in the rubber grommet hole and apply some vacuum to it from a running engine.
Unless you happen to have a vacuum pump handy?

Optimally it be nice to have a shut off valve in the hose so you can isolate any vacuum leaking to the main diaphragm and not a faulty check valve.
If it loses vacuum, it needs to be rebuilt.
If not, press the pedal rod on the back of the booster and see if the poppet valve opens.
You should hear the vacuum release.

I didn’t ever done it, but that seems like it would work.
Ok thanks, I'll gather the stuff.

Sent from my SM-S901U using Tapatalk
 

Timmy390

Contributor
Bronco Guru
Joined
Jan 1, 2011
Messages
5,626
Loc.
Conway, AR
The one you have is not s stock Bronco booster so the one you get will look different.

Tim
 

Timmy390

Contributor
Bronco Guru
Joined
Jan 1, 2011
Messages
5,626
Loc.
Conway, AR
Ok. But any 8 inch will work correct, maybe even a 9 inch?

Sent from my SM-S901U using Tapatalk
That I don't know. I have the stock version. I see the one like you have in "kits" sold for the Bronco. It's like the vintage mustang boosters. You have stock and then all the others people sell with kits.

Tim
 
OP
OP
daddycreswell

daddycreswell

Contributor
Bronco Guru
Joined
Jul 30, 2011
Messages
2,744
Loc.
Lebanon, TN
That I don't know. I have the stock version. I see the one like you have in "kits" sold for the Bronco. It's like the vintage mustang boosters. You have stock and then all the others people sell with kits.

Tim
Ok, thanks. From what I've read bigger is better and the more diaphragms the better.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,645
And no matter what you have, if you’ve already got it all set up for your bronco, there are still rebuilders out there that can take it in and send it back to you like new.
We’re lucky that we still have one local here. But I’m sure they’re like most other shops and are much fewer and farther between than they used to be.
But if you were in any kind of an urban area, look for brake booster rebuilders.
Not sure what else they would specialize in, but you can often search them out under other parameters.
We have a brake, a steering, and several alternator/generator rebuilders still around.
 
OP
OP
daddycreswell

daddycreswell

Contributor
Bronco Guru
Joined
Jul 30, 2011
Messages
2,744
Loc.
Lebanon, TN
And no matter what you have, if you’ve already got it all set up for your bronco, there are still rebuilders out there that can take it in and send it back to you like new.
We’re lucky that we still have one local here. But I’m sure they’re like most other shops and are much fewer and farther between than they used to be.
But if you were in any kind of an urban area, look for brake booster rebuilders.
Not sure what else they would specialize in, but you can often search them out under other parameters.
We have a brake, a steering, and several alternator/generator rebuilders still around.
I'll look around, but I it's not setup on the Bronco. A member just sent it to me the other day. I thinking I'm just going to replace the booster part, he couldn't recall if it was blown or not.

Sent from my SM-S901U using Tapatalk
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,645
Should not have. They might have relocated the wheel well/inner fender, but the actual dimple/stamping clearance was first in '76 officially I think.
That's because power brakes were not an option until disc brakes appeared.
Unless someone has a '75 with factory power brakes to show us! Maybe a Marti Report?
That would be interesting to find the first instances of dimpled (what's the correct term here?) wheel wells.

Paul
 

SteveL

Huge chevy guy
Joined
Jun 24, 2001
Messages
11,656
Loc.
Hawthorne ca
It's a bc set up. Originally they used a mustang 2 booster. Maybe78 for the year. When the supply got short he swapped to that style on it. It's designed to clear any of the inner fenders. You may be able to walk it in to a napa and get a replacement. If you find a rebuilder bring the complete set up with mc and they might be able to set up the push rods correctly on the bench
 
OP
OP
daddycreswell

daddycreswell

Contributor
Bronco Guru
Joined
Jul 30, 2011
Messages
2,744
Loc.
Lebanon, TN
It's a bc set up. Originally they used a mustang 2 booster. Maybe78 for the year. When the supply got short he swapped to that style on it. It's designed to clear any of the inner fenders. You may be able to walk it in to a napa and get a replacement. If you find a rebuilder bring the complete set up with mc and they might be able to set up the push rods correctly on the bench
I'm just going to get a new one, and a new MC.

Sent from my SM-S901U using Tapatalk
 
Top