I want to drop a dual master in my 49 pontiac. I have seen something before using a 57 Chevy swing pedal, which I have, but need to know what master to use and what I need to pay attention too. Also if there is a dual under the floor stock location setup anyone makes. I have seen some for 49-up chevy but nothing for pontiac. I know frames are different. Any help would be much appreciated, I need to finish up the brakes and get the car rolling for when the weather breaks.
This was posted earlier http://www.jalopyjournal.com/forum/showthread.php?t=308693&highlight=pontiac+master+cylinder Are you keeping the drum brakes , than use a late 60's mc from a Chevelle with drum brakes. I've seen that set up on a 56 chevy that was converted over. I'm putting a 55 Chevy hanging pedel assembly on the firewall in my 55 Pontiac. I'm using a Mopar master cylinder from a 85 5th ave. It's very similar looking to the Wilwood master and has a 1 1/8" ? bore I believe, it's the same master weather power or manual brakes. I also grabbed the proportioning valve set up from the same car since i'll be using disc brakes.
Just grab any 55-60 Chevy pedal assembly, or even a 58-up Pontiac one. Run a manual brake master for an all drum 68 Chevelle or Nova (same P/N) - The stock underfloor Pontiac master is set up different from a Chevy and the frame has an X in it - it would be difficult at best to try to set it up the way the Chevy units are converted over with a rod through the old M/C bore, because it would probably have to go through the frame rail.
Might be stupid question but the bracket to the firewall mount has 4 studs and the master cylinder has 2 mounting holes is there a plate I need to make it line up correct for between the bracket and mc?
If your using the gm dual master from late 60' and 70's the spacing is the same as the mounting bracket, use the bottom two holes , the top 2 use nuts and bolts to hold the bracket assembly to the firewall. This was for a manual brake master. BTW I had to trim the pedel assembly on mine to fit behind the dash. And i'm only using 3-4" of the stock pedel arm, to mount the master where I wanted it, I'm using the bottom section of a brake pedal arm from a ford truck, it's quite a bit longer and has a higher offset to mount it furthur from the engine. You need to make sure the brake pedal is in a safe and comfortable position to work properly.
I have 57 pedal assembly and will be using your recomended master, I figured I would have to trim something since it wasnt made for it. Will have to remove the heater core since that is where the new msater will go.
I made up an 1/8" plate to cover up the firewall in that area also to add rigidity outside of just mounting for the master.
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