Brake Booster Install

hendrixftw22 · Sep 29, 2024

Hi! I am trying to install the brake booster on my 71 Mach 1 factory manual drum brakes. We have completed the disc brake conversion on the front and now are ready to install the brake booster. We have removed the master cylinder that was originally on it and now see that there are the two holes the master cylinder was threaded into and then two studs below. I have read in some other forums that we might need to drill these studs out. However, our kit instructions say to drill out 4 new holes for the brake booster to be installed. Is this correct?

If so, do we need to remove the bracket holding the pedal that is there now? Any feedback/guidance would be appreciated!

Steve McMahan · Sep 30, 2024

Can you post a pic if those installation instructions regarding the drilling? Usually, when you do a front disc brake conversion, you replace the existing master cyl because the front disc master has a larger brake fluid bowl. Good luck.

Stanglover · Sep 30, 2024

I replied to your questions in Marks1 post. Converting manual drums to factory disc.....
What booster are you trying to install.

Hemikiller · Sep 30, 2024

If you were converting to a factory booster and pedal, you can simply use a 7/16" drill bit to clean the threads out of the weld nuts on the pedal bracket. No need to remove it, just run the drill through.

If you're using an aftermarket booster, then maybe a call to the manufacturer might be in order.

Stanglover · Sep 30, 2024

As a new member, we'd love to hear more about your car with some pics, we love pics!
There is a section for Introductions.
Welcome from SW Ontario, Canada.

hendrixftw22 · Sep 30, 2024

Stanglover said:
I replied to your questions in Marks1 post. Converting manual drums to factory disc.....
What booster are you trying to install.

Here are a few pictures of the booster we have. We got the entire kit from Leed Brakes. I also included a picture of our current firewall with the holes and studs after removing the master cylinder. I also have a picture with a cardboard template of how the booster would line up now. It seems similar to your post where we would need to modify the hole for the pushrod lower than where the master cylinder was originally located.

hendrixftw22 · Sep 30, 2024

Stanglover said:
As a new member, we'd love to hear more about your car with some pics, we love pics!
There is a section for Introductions.
Welcome from SW Ontario, Canada.

Absolutely, I will do so now!

Stanglover · Oct 1, 2024

hendrixftw22 said:
Here are a few pictures of the booster we have. We got the entire kit from Leed Brakes. I also included a picture of our current firewall with the holes and studs after removing the master cylinder. I also have a picture with a cardboard template of how the booster would line up now. It seems similar to your post where we would need to modify the hole for the pushrod lower than where the master cylinder was originally located.

I'm not familiar with the Leed Brake booster, but many have chosen that one. It looks to be identical as far as bolt pattern goes. As for the cover plate seen in your pic d4b**** I honestly don't remember if that just came out when I removed the peddle bracket or whether I had to cut it out. The firewall was obviously made for both scenarios with the cover plate inserted when manual brakes were used. Oh wait!! I see two screws that I think are self tappers used to hold that plate in place. I'm pretty sure that's it.
There are a couple of posts going right now on this subject, go back through the others as I'm sure some of your questions are asked and answered there.
One more item, you'll need a different stop light switch if I remember.

Hemikiller · Oct 1, 2024

The cover plate will come out when you remove the two sheetmetal screws from the inside, and the lower fasteners which are studs. They will unthread from the pedal hanger bracket. It's been over twenty years since I converted a drum car to discs, but there *may* be a spotweld or two holding it in place.

Stanglover · Oct 1, 2024

Hemikiller said:
The cover plate will come out when you remove the two sheetmetal screws from the inside, and the lower fasteners which are studs. They will unthread from the pedal hanger bracket. It's been over twenty years since I converted a drum car to discs, but there *may* be a spotweld or two holding it in place.

View attachment 93613

Your memory is better than mine!!

hendrixftw22 · Oct 1, 2024

Hemikiller said:
The cover plate will come out when you remove the two sheetmetal screws from the inside, and the lower fasteners which are studs. They will unthread from the pedal hanger bracket. It's been over twenty years since I converted a drum car to discs, but there *may* be a spotweld or two holding it in place.

View attachment 93613

How do we go about getting those studs out? Should we go ahead and drill them out? Also, where did you find this diagram? Is there a website or a book we can purchase?

Stanglover · Oct 1, 2024

hendrixftw22 said:
How do we go about getting those studs out? Should we go ahead and drill them out? Also, where did you find this diagram? Is there a website or a book we can purchase?

The mind works in mysterious ways. I was at the gym just now when I remembered what to do with the studs (I think). They unscrew. you'll probably need to spray with penetrating oil around the base of the studs. Use two nuts, one as a jamb nut against the other and they should come out. Then you can drill the holes out with a 7/16" bit. I think any remaining weld nut that was on the back (bracket) will not interfere.
If I'm wrong, then my old mind is worse than I thought!!
Let us know if that works.

Hemikiller · Oct 1, 2024

Just like Stanglover said, they unscrew - they're doubled ended studs. I can't remember if I used the jam nut method or vice grips, it was 1991 the last time I did one of these.

The image is from the Ford assembly manuals. You can get them in print, CD or USB. I bought the CD and saved it to my cloud server. A little pc magic can get rid of the watermarks.

https://www.npdlink.com/1965-1973-m...factory/electrical-assembly-manuals?year=1973

bucketlist fastback · Oct 2, 2024

If nobody else has mentioned this, when using the booster you need to have the power brake pedal. Intended for boosters are approximately 2 inches longer and mount on its own pivot. You might want to go on YouTube. There are guys there on YouTube that have installed roller bearings on their clutch pivot. You can see the pedal hanger out of the car. Don’t worry if it’s not your exact year the hangers are all similar. Knowing the difference in those brake pedals is important.. pretty sure there are aftermarket pedals available for use with booster however, you might have to cut the pedal pad mounts because the pedal pad me maybe only made for automatic transmission

bucketlist fastback · Oct 2, 2024

To do the job right you really need to get that pedal hanger out of the car. Everything will be much easier to see about the studs and also opening up that pass through hole where booster mount. Plus seeing where that new power pedal mounts

Stanglover · Oct 2, 2024

bucketlist fastback said:
If nobody else has mentioned this, when using the booster you need to have the power brake pedal. Intended for boosters are approximately 2 inches longer and mount on its own pivot. You might want to go on YouTube. There are guys there on YouTube that have installed roller bearings on their clutch pivot. You can see the pedal hanger out of the car. Don’t worry if it’s not your exact year the hangers are all similar. Knowing the difference in those brake pedals is important.. pretty sure there are aftermarket pedals available for use with booster however, you might have to cut the pedal pad mounts because the pedal pad me maybe only made for automatic transmission

The push rod pin position is 2" lower than on a non power pedal arm. I don't think the actual arm length is 2" longer because it would be too close to the floor and restrict operation. Here's a pic of what I did.
I do agree that it would be better to pull the bracket to install the booster.
Our friend has a 302 with a 3 speed, so yes, pull the bracket and add a bearing kit for the clutch. I have posted on doing mine, but that was several years ago now. I chose the Mustang Steve kit, but in actuality as a machinist, I could have made my own. I can elaborate later if required.

Bill Kanode · Oct 2, 2024

Stanglover said:
The push rod pin position is 2" lower than on a non power pedal arm. I don't think the actual arm length is 2" longer because it would be too close to the floor and restrict operation. Here's a pic of what I did.
I do agree that it would be better to pull the bracket to install the booster.
Our friend has a 302 with a 3 speed, so yes, pull the bracket and add a bearing kit for the clutch. I have posted on doing mine, but that was several years ago now. I chose the Mustang Steve kit, but in actuality as a machinist, I could have made my own. I can elaborate later if required.

I am replacing the nasty looking booster and master cylinder with new Leeds setup in my 1971 fastback and changing from FMX to a top loader 4spd. I was able to score a NOS brake pedal for manual brakes and lowered the pin 2" and welded the old hole to keep strength in the pedal. I then used a Scott Drake roller bearing and attached it to the slots in the pedal bracket for the clutch pedal from Modern Driveline.

hendrixftw22 · Oct 7, 2024

@Stanglover @Hemikiller @bucketlist fastback @Bill Kanode
Thank you all for your help! We got everything installed and working properly this weekend. Minus the power brake light switch which we will get this week and install. I appreciate everyone!

basstrix · Oct 8, 2024

I noticed that Rock Auto has Cardone brake boosters back in stock for our cars.

bucketlist fastback · Oct 26, 2024

bucketlist fastback said:
To do the job right you really need to get that pedal hanger out of the car. Everything will be much easier to see about the studs and also opening up that pass through hole where booster mount. Plus seeing where that new power pedal mounts

This video is very informative. The guy is fixing the clutch pedal but pedal hangar detail is very visible. This one has power pedal and separate pedal pivots that I was referring to. Cars with manual transmission and manual brakes share same pivot. There is a difference.

bucketlist fastback said:
To do the job right you really need to get that pedal hanger out of the car. Everything will be much easier to see about the studs and also opening up that pass through hole where booster mount. Plus seeing where that new power pedal mounts

Brake Booster Install

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