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I've got a 31 Ford 4 Dr.Deluxe Town sedan with a 70's Mustang brakes (disk/drum). The original builder put a Mopar master cylinder on the firewall instead of below the floor. It takes MEGA pressure to stop so I want to add power brakes. Because of the firewall mounting and the engine set back, putting a firewall mounted booster is not possible. I also tried to use an under floor unit but not enough room. I have plenty of vacuum to operate a booster so I'm thinking of a remote unit but can't seem to find one.

One idea I had was to mount a clutch cylinder on the firewall and use a slave cylinder to push on the booster where the pedal rod would be. Has any one tried this??
 

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I have seen that setup on a couple of cars, so it isn't unheard of.

But first..

Have you considered putting a smaller master cylinder in place of the chrysler M/C and have you checked your pedal ratio?

You should have 5:1 to 7:1 pedal ratio for a manual M/C. With that ratio you should be able to have at least 7/8" travel at the master cylinder pushrod. Most M/Cs have the ability to travel 1".

If your pedal ratio is good try going down 1 size on your master cylinder. I would think 15/16" or 1" would be a good size for that.

ECI has a good webpage that tells you how to measure your pedal ratio. http://ecihotrodbrakes.com/brake_facts.html



Hope this helps,
Mikey
 

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On my 30 model Ford I used 11 inch Chevy disc on the front and Chevy drum brakes on the rear. I used a firewall mounted 72 Thunderbird master cylinder. It stops really good.
 

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Like Mikey said, this will likely be your best least downtime solution and should solve the problem. It is rare for these early cars to require power brakes or steering.
 

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One idea I had was to mount a clutch cylinder on the firewall and use a slave cylinder to push on the booster where the pedal rod would be. Has any one tried this??[/QUOTE]

That is the system I have on my T. Has a fruitjar on the firewall running a nonboosted 91 Caddy master in the trunk. Works well. I make no claims as to suitability or safety of this system. There are remote boosters on the market, but I have not seen one in operation. :)
 

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Try a 70 mustang master cylinder. It worked on that car and thats the brakes you have. Check the pedal ratio and copy the mustang. Sounds like the MC you have has to large of a piston diameter.
 

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Discussion Starter #7
Thanks All:

Thanks to all of you that replied. I did check my pedal ration and it is about a 8:1. In fact, I need to shorten it about an inch since it's too close to the floor and I end up pushing with the instep of my foot, not the ball. The builder put the brake pedal on the left of the steering column. There is no room on the other side. I think he made the transmission tunnel too wide. I have a non-power setup in my Legends race car and it takes little effort and I get great feedback. Of course it only weighs 1100 pounds.

The idea of a smaller bore master sounds great. I think the Mopar is 1 1/16 or so. I also want to thank Mark at ECI. They are not far from me and he has been a great help in trying to figure this out.

Larry
 
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