Question to the crowd. Can anyone recommend a brake master cylinder for the following? 1941-46 Ford stock front drum brakes, 1" cylinder. 1955 Ford stock rear drum brakes, 3/4" cylinder. Application is a 1931 Ford Roadster project, thanks,,,,,,,,,,,,,
I have always tried to match the bore size as close as possible with what ever the front brakes were equipped with for a bore size, as well as what size brake tubing to use for the hard lines. The rear brakes are much more forgiving since the front do the majority of the stopping. 39 to 48 ford master cylinders had a 1 1/16 inch bore size along with 1/4 inch brake hard lines. If you stay true to what front brakes originally used you will have a good well functioning brake system. The engineers designed it the way they did, so why try to redo what they did. On my 39 sedan, I am using F100 front brakes with an early bronco 9 inch rear with 10 inch drums. The early ford and F1/F100 share the same bore size as an early ford master (39 to 48) at 1 1/16th inch. I like to use the early vette / chevy style large reservoir master cylinders because i like the volume and you can get them now with ports on both sides to aid in hard line connection choices. I use a 1 1/8 inch bore early vette type master as it is the closest I can find to the factory size. Also I use 1/4 brake lines as well for the front since that what they used. Volume is important and you don't have near the volume in a 3/16 brake line that you do in a 1/4 inch line. My 39 is the best stopping old car I have ever had. It's actually better than the roadster that was built with 4 wheel disk brakes. Stay with the original specs and you won't have any issues.
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