hi, i'm working on a 1951 victoria coupe. 8BA, 3 spoiled B.W. O.D. i'm thinking about doing the front disc conversion and i know i need to replace the master cylinder. i'm buying the kit from shoebox central and was looking at there offering for a master cylinder and was wondering if anyone has a better option. is it best to just go with the kit they offer at around $400 or is there a firewall mounted one out there that would work better and may be a bit cheaper? if i need to make new lines anyway, would i be better off with one that isn't under floor mounted?
Just stick with that kit. There's nothing wrong with underfloor MC, I've put thousands of miles on cars with the MC under the floor. Plus they look like***** hanging off the firewall. Not to mention to need to hang the pedal, etc... for what gain?
Some body here was complaining about stopping pedal pressure on a shoebox and went to a stepped MC from an S-10 pickup I believe. They were not running vacuum****ist.
A stepped master can save the day. I have really only seen them in pickup trucks over the years, OG issue of course. Pedal ratio is also key, likely yours should be okay as Ford made it. The one in my car is a straight up 1" bore from Speedway, a Ford Fairlane/Mustang disc-drum type. No power, the car stops like a manual-brake '72-ish GM mid size car.
In my 51', I used a brake pedal****emble from a 57' Ford, mounted master on the firewall, dual master cylinder from a early-mid 70's Fairlane, Mustang, Galaxy and no booster
It really comes down to your fabrication skills, and how well you can make parts work. I personally have always used factory master cylinders for builds, or upgrades to disc brakes. I prefer using something that's already been engineered, and I can buy a replacement master or kit at any auto parts store. Getting the pedal ratio correct is not that complicated, and there are numerous mounting systems for either under floor, or on the firewall that use factory master cylinders. It's just a case of what it takes to bolt or weld them to your existing car, and then plumb the lines. And I would always plan on installing new lines end to end when changing any old car from single pot master and drum brakes to a dual pot master and disc/drum or disc/disc brakes. If you choose to convert to a firewall mounted master, the area on the firewall will need reinforcing to avoid flexing the firewall when applying the brakes. A large piece of 1/8" thick steel plate can be bolted or welded to the inside of the firewall to spread the load, and avoid flexing, or breaking out the firewall sheet metal.
My firewall had a lot of flex. The OG master had 4 bolts to secure it to the brake pedal bracket inside the car, new masters are 2 bolt. I made a plate from 1/4" aluminum, actually made 2 but not stiff by far. I went to 1/4" steel, much better, I still have minor flex but can live with it. I should have added a 1/8" or 3/16" plate inside the car.
Leave it alone. There is no real advantage to changing any brake parts on that car. Done right, they will stop on a dime.
On some installations you might also consider making a brace from the pedal****embly inside to the dashboard too. I have the pedal****embly bolted to my plate, and also braced to the dash on my '39 and it's rock solid.
Firewall mounted master means swinging pedals. That means fabrication. If you are prepared to fab the the linkages required or have access to the parts and pieces you need a firewall mounted master is nice. I don't think that they are any better but they are nice. If they are offering a master that is matched to your setup I would probably go that route. My experience is that nothing is a bolt in so be prepared to cut and or generally Jill flirt some things. But that's hot rodding.
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