Brake Booster Help!

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MuuMuu101

MuuMuu101

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My friend and I need some brake booster help. We don't know wtf this thing came off of. It almost looks like some generic aftermarket unit or something off of a Gm vehicle or something. Looking into it, the previous owner hacked up and cut up the previous studs, cut a larger hole in the firewall to make the booster fit, and bored out the old MC mounting points so that it would fit the booster. My friend and I are just thinking we should pull the booster and go from there since we don't know what the hell it is and it's not really going to help us from here on out.

So we need input on where to go from here. Anyone know what the booster came off?

Here are some crappy cell phone pics.
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O, and they shaved off the little mushroom pushrod adjuster mabober...
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Sorry, it's a 1968 Dodge Dart with Kelsey Hayes disc brakes in front and 10" drums in the back.
 
Any suggestions? Does anyone know if anyone sells the brake support mount with the studs and stuff that goes under the dash?
 
That's probably what we're going to end up doing. Maybe just use the MC I bought from NAPA and use it as manual brakes w/o the booster.
 
I don't thing a 60's GM booster since those are angled up and don't use a lever arm like Mopars. Since a 2 bolt MC, it might be after-market or maybe from an 80's car. Did it attach to the brake pedal correctly?

I have the brake assembly from a ~74 Dart automatic I don't need. This is both pedals and the bracket that goes between the dash and firewall. It has 4 studs that go thru the firewall. However, in reading about adapter plates, they say later cars were different w/ bolts coming from the engine bay, so I'll check. Free if you can pickup in Sacramento.

However, it looks like you have the bracket and somebody just hacked off the studs. If the booster fit OK, put it back and install a 2-bolt aluminum MC. I plan to put a 2 bolt MC (95 Breeze ABS) on my 64 Slant for manual brakes. I just drilled 2 holes thru the firewall and bracket to nestle it between the 4 unused studs, with a big washer to cover the opening. Seems like it will work, but might run into something.

If you want to do better, buy the $40 2- bolt MC adapter plate. Get the one for cars without studs since yours are gone.
 
BillGrissom said:
I don't thing a 60's GM booster since those are angled up and don't use a lever arm like Mopars. Since a 2 bolt MC, it might be after-market or maybe from an 80's car. Did it attach to the brake pedal correctly?

I have the brake assembly from a ~74 Dart automatic I don't need. This is both pedals and the bracket that goes between the dash and firewall. It has 4 studs that go thru the firewall. However, in reading about adapter plates, they say later cars were different w/ bolts coming from the engine bay, so I'll check. Free if you can pickup in Sacramento.

However, it looks like you have the bracket and somebody just hacked off the studs. If the booster fit OK, put it back and install a 2-bolt aluminum MC. I plan to put a 2 bolt MC (95 Breeze ABS) on my 64 Slant for manual brakes. I just drilled 2 holes thru the firewall and bracket to nestle it between the 4 unused studs, with a big washer to cover the opening. Seems like it will work, but might run into something.

If you want to do better, buy the $40 2- bolt MC adapter plate. Get the one for cars without studs since yours are gone.
Click to expand...

It attached to the brake assembly correctly, however the master cylinder bolt holes were drilled and widened in order to fit on the booster. Plus, in order to mount the booster they drilled for holes into the firewall and straight into through the pedal assembly. I personally wouldn't reuse the booster. I think I added a picture above of the little adjuster that goes in the booster that someone sheared off. That should actually be a mushroom shape. The studs were basically cut off and someone took a grinder to the firewall to fit the pushrod through the firewall. When the booster was installed and you look at the pedal assembly from the inside of the car, you can see additional holes in the firewall.

I may be getting someone to cut something out from a spare firewall (with the studs) he has so that I just prep the metal and weld it in place. I still don't know if a 1.03" bore is good for manual brakes so I'm still on the fence.
 
I could be wrong..which 90% of the time I am...but that looks a lot like the booster that was on my 76 Cadillac El Dorado.
 
Since yours is a later car (collapsible steering column), I don't know for sure, but in my 65 Dart, the studs you speak of are part of the brake pedal support and not the firewall. Might be easiest to get another one. If an automatic car, those are easy, if manual, everybody wants one, so maybe add bolts to your bracket. If I was headed south, I would bring the one I have to you, but not any time soon.
 
BillGrissom said:
Since yours is a later car (collapsible steering column), I don't know for sure, but in my 65 Dart, the studs you speak of are part of the brake pedal support and not the firewall. Might be easiest to get another one. If an automatic car, those are easy, if manual, everybody wants one, so maybe add bolts to your bracket. If I was headed south, I would bring the one I have to you, but not any time soon.
Click to expand...

Sorry I forgot to update this thread. I've been talking to the guy with the firewall and he's been guiding me through it. You are correct, the studs go through the pedal assembly. However, in order to install the booster, the previous owner drilled 4 holes through the firewall and pedal assembly so he can throw some bolts on there. So I might be getting that bracket as well from him.

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