Super duty brake booster into a dent side

[Broncokyle88]

Since we are pretty much starting from zero on this new site, I figured I might as well add some pretty basic tech. Any bit of tech will help drive traffic. And also fuck FTE

In my on going quest to be able to daily drive my 79 f250, brakes that actually stop it are next up. My original booster was blown, a previous owner had cut the end off of the factory rod and welded it to another one to make it work, and the fuckers want right around $200 for a reman, if they can even get it! So I went with a vacuum booster out of a 2001 f250. Mainly because it was free. It’s a dual 11” diaphragm booster which should yield better performance than the 9” stock one. I like using off the shelf parts, because finding custom shit when you are broke down in buttfuck Montana sucks. The only modification to the booster required is to cut off the booster studs, they are way too long, I think I ended up cutting them down to 1” or so, and that’s a customization I’m willing and able to make on the side of the road.

So, as anyone who’s had the pleasure of changing out a booster on one of these things knows, the booster doesn’t bolt to the firewall, it bolts to a bracket that attaches to the firewall, and is a royal **** to try to remove. We are going to make a new bracket to adapt the newer booster to the firewall. Access doesn’t get any better with the new bracket and booster, but I didn’t see any other way to make it happen using stock parts. Yes, you could swap a hydrobooster directly to the firewall, but all the ones I looked at would have required cutting and welding to change the length of the push rod, plus they weren’t sitting on my shelf already. Did I mention free parts I was never going to use otherwise? I’m sure I could bolt a hydrobooster off of a 2001 f250 right onto my bracket and rock on if I ever have an issue with this booster.

The bracket is made with drops of 1/8” plate I had laying around. If I had 3/16” I’d have used that instead. I encourage anyone building their own booster bracket to use 3/16”, and if I have any issues in the future I will remake this bracket with 3/16”. And if it holds up fine, I’ll probably still add gussets whenever I tear the truck down for body work.

Enough words, time for pictures (and more words)

 

[Broncokyle88]

This is what we are making here. We need 4 pieces of plate for this bracket. I’m giving rough measurements here, I would definitely double check them against your own truck. I’m a drunken hill billy, don’t take my measurements as gospel.

booster plate is going to be 4 1/8” vertical x 4 7/8” horizontal. Bore a 3” hole in the center of the bitch, and drill 4 7/16 holes in it. You are working with a 3” x 3 3/4” bolt pattern. 3” is the vertical separation, the 3 3/4” is the horizontal.

the firewall plate is 4 3/8” square, this one is kind of important because the body seam on the firewall limits you on width. This one gets 4 7/16 holes too. They are on a 2 1/8” vertical x 3 1/4” horizontal pattern. Measure up and in 1/2” from the bottom edge and side to mark your first set of holes. Then measure up the 2 1/8” and mark a line across the whole plate. 1/2” from the sides gets you your bolt holes, then mark the center line of the plate (2 3/16”ish), and that intersection will give you the center mark for your pushrod hole through this plate. The hole is centered between the bolt holes, and shares the same horizontal center point. Hog out a 2” hole in her, and you are good to go.

All you have left is the side plates. You need two of them at 2 1/4”x 4 7/8”. These will require some notching, but since I suck at measuring I just notched them out during mock up when I could see what needed to be removed. I ended up cutting about 9/16” deep, and about 1 3/4” long. You can see the notches good in the first and second pictures. You can see what I did to gain the clearance necessary for the booster to seat. You have to do this because the side plates have to go 2” apart or else you will not have clearance to get a wrench on the bolts to bolt the bracket to the firewall.

You can see here how the bracket gets put together. Tack the side plates to the firewall plate centered on the plate 2” apart, making sure to orient it in this manner and flush to the bottom of the firewall plate. Then test fit the booster plate, making sure it’s flush with the opposite end of the side plates. We need the bracket to be offset. Cut and/or grind your notches into the side plates, and then tack the booster plate in place. Burn the thing together, then spray it in the finest $1 spray paint you can get your hands on. If you want to get fancy, you can even clean the mill scale off

 

[Broncokyle88]

This is a giant ass rubber ducky. It holds no importance in this project, and it is 100% possible to do this without him. But a giant rubber ducky is awesome, so everyone who doesn’t like it can fuck off

 

[Broncokyle88]

Here we see the problem with the stud length. All you have to do is cut the studs. I didn’t cut enough initially. Trim them enough that you can easily start the nuts for the booster when it’s in the hellhole that is the truck

And a 5 gallon bucket holds the booster like a champ, you don’t have to fight with it test fitting shit or worry about it rolling off of your work bench

 

[Broncokyle88]

This is the only real one off custom part for this setup. This is a bushing for the pedal rod. It’s chromoly. It doesn’t need to be chromoly, cast iron would probably be best. Bronze would be fine too. Looking around on McMaster Carr for five minutes yielded a couple of results, so an off the shelf piece could be had. I’m just impatient. 5/8” od, sized for a 3/8” bolt, with a flange. I used a new 3/8” x 1 1/2” flanged bolt, a flanged nut, and a nylock lock nut to hold it all together. I put the flange of the bushing between the pedal rod and arm. Everything seems happy and moves freely

 

[Broncokyle88]

Next step is bolt your bracket to the firewall. I used new 3/8” x 1 1/4” coarse flange bolts. Anyone who owns a dentside should have a 9/16 shallow universal socket, and now is a great time to use it. You can actually get a ratchet on all 4 bolts if you use one of these.

 

[Broncokyle88]

Next step is to bolt the booster to the bracket. The nuts are m8, and take a 13mm wrench. You want a flex head ratcheting wrench for this. Set the booster in the bracket, start a nut or 2. And then go inside and make sure the pedal rod is on the left side of the pedal arm, and install the bushing and bolt. It’s a lesson I’ve learned before, if you don’t do this it’s guaranteed the push rod is fucked off to the wrong side and you have to take everything apart to fix it. Start the rest of the booster nuts, and tighten them down. Hopefully you were smart enough to break the edges on everything. If you are stupid like me, you are going to bleed. Then go back and tighten up the pedal bolt. The 79 master cylinder will fit, but I’m not happy with the push rod length, and I’m waiting for a 2001 f250 master to show up. It’s a bigger bore, and should be disc ready for when I go to disc on the 60 rear. I’ll swap that puppy on there, dick with making new lines to fit what I assume is the metric master cylinder, maybe fit a proportioning valve, replace all my vacuum lines, and then I’ll have a performance report.

Items of note right now are I’m pretty sure you won’t be able to pull tall valve covers with the booster installed if you are running a big block or an fe. I have a Windsor that a previous owner stuffed in, so I’m good on room. Hydroboost is always an option if that’s an issue for you.

 

[Broncokyle88]

And a picture of my victim, plus another of the giant ducky, because I think they are both awesome

 

[JR4X]

Nice tech!

Is the booster for a gasser SD?

 

['84 Bronco II]

Nice tech!

Is the booster for a gasser SD?

Should be, the diesels are all hydroboost to my knowledge, and I haven't seen a '99-'04 F250/350 gasser with hydroboost.

 

[Broncokyle88]

Nice tech!

Is the booster for a gasser SD?

The booster was originally for a v10 truck. I don’t believe ford messed around with vacuum pumps on the diesels when they went to the super duty chassis

 

[JR4X]

I've had a few superduty gassers. One 5.4 and three 6.2's.I don't remember what any of them had for brakes. That's a big ass booster!

 

['84 Bronco II]

The booster was originally for a v10 truck. I don’t believe for messed around with vacuum pumps on the diesels when they went to the super duty chassis

Unfortunately they did; the HVAC controls are vacuum operated (on the '99-'04 trucks at least) At least it is electric and not engine driven.

 

[Broncokyle88]

I've had a few superduty gassers. One 5.4 and three 6.2's.I don't remember what any of them had for brakes. That's a big ass booster!

Yeah, It is pretty massive. I though I had an uh-oh for a minute and I had trapped my master cylinder between the washer tank and the fender. A little bit of persuasion got it past the booster studs though.

Honestly, a super duty hydroboost set up is the way to go. Better performance and more room under the hood. But I didn’t feel like running down fittings and making lines that would work, or upgrading my marginal power steering pump. It works fine just doing steering, but I don’t think it would be happy running the brakes too. In the future I plan on swapping to efi and a serpentine set up, and since I have a Saginaw bracket I’ll probably change to hydroboost when the pump gets swapped out. This was almost free, and it stopped hundreds of thousands of trucks just fine, so it should work good on here too

 

[Broncokyle88]

Unfortunately they did; the HVAC controls are vacuum operated (on the '99-'04 trucks at least) At least it is electric and not engine driven.

I learn something new every day. That sucks (all vacuum operated hvac shit does) but I’m more okay with it only running the hvac instead of making it run the brakes too

 

[Broncokyle88]

More pictures. This is the old busted ass booster. I have zero issue with people cutting the ends off of pedal rods and welding to make shit work, but please, for the love of god, cut the old fucking end off of the rod

 

[Broncokyle88]

Here’s some pictures showing the size of the booster, and the valve cover clearance. Once again, this is a Windsor block that was swapped in at some point in time (I honestly believe its a 302). The clearance I have is not what anyone else will have with a m series, fe, or big block. With my short valve covers, I can get away with yanking them without removing the booster. If you are running tall valve covers, even on a Windsor, I don’t think it’s going to happen.

I also provided a shot of the rough overall width of the booster, and the distance it sticks out from the firewall. For comparison, my old booster had a body that was 5” thick. The super duty booster is about 7.5”

Again, I’d highly recommend building the bracket and swapping in a hydroboost system.

 

[bobbywalter]

That's about the same way I put gm hydroboost in my ranger which came with the 6.5 diesel.... Piece of pipe and some 3/16 shim stock for load posts .... Burned em together at the length the pushrod worked best.


With the bonus of the boost upgrade at your leisure....perfect. good work and documentation.