70 Aftermarket Brake Booster - Modify Firewall/Bracket?

[PurpleBeeper]

I had a brake issue YIKES!!! and I decided to get a new master cylinder & brake booster for my '70 Roadrunner power front disc/rear drum car. My original booster went out back in 1990 and I replaced it with one from a power drum/drum brake car since that was all that was available at the time. Anyway, there's a new reproduction brake booster out there and I bought one from "pirate jack".

The references I've seen say "hub of booster is larger than original and requires some modification" which I "think" might be the big hole in the firewall has to be enlarged or maybe a bracket around that hole inside the car?

Has anyone put on one of these repro brake boosters? What kind of modifications do I have to do? I want to be prepared when the part arrives. Thanks!

 

[Malicious]

I fitted the Pirate Jacks set up, been a while now but it fit fine form memory. I did have to clearance the backing plate that come with it that sandwhich's in between the booster and the firewall but other than that, bolt up affair. No issue with it. I did have problems with the mater cylinder, but that was a crap rebuild from cardone rather than pirate jack.

I'd recommend it.

Good luck!

 

[PurpleBeeper]

I had to take a dremel with a high speed cutter on it & grind about 1/16" all around in the center hole for the booster. That included a little bit extra where the metal inside the car didn't 100% line up with the hole in the firewall. I just hit the bare metal with a touch of primer & the booster went in. Now I'm trying to get that #@($* nut/bolt back into the brake pedal pivot & through the hole in the rod on the back of the booster. Anybody know a good trick to get that top bolt back in? There just isn't enough clearance between the edges of the pedal assembly to let you slip the bolt into the hole.... help!

 

[Malicious]

If your talking about the long solid bar that is the main pivot point for the pedal its self that goes through the pedal 'box' frame, then yeah I just recently did this and it's a massive @&$)*%.

The way I did it was to remove the lower column trim, loosen the column, remove or move the ac tubing, I have the fresh air vent removed as well.

Laying on my back in the footwell I slipped the nut into the gap from above. Moved it around with a combination of fingers and flat head screw drivers to get it near the hole and slip a wrench onto it. The 12mm/ 1/2 wrench on the flare we end of the bar and keep twisting until it caught.

Not fun. Add to that I didn't know what size the nut was, so I had to do it threat times before nailing it. Good lighting will help, I think I had an led light sitting on the inside lip of the lower dash to get the light inbetween that little viewing gap.