Master Cylinder Upgrade

[kyudizky]

I know its been talked about a number of times on here, and i've tried to use the search as best i can.....

Need to covert my single bowl master cylinder to dual. Is there a kit sold that anyone is aware of? I have read that using a '67 Mustang Dual MC is recommended or is something else better/easier? I just need to make sure I get everything i need and what i get will work with my car.

My car is a '64 vert. V8, and previous owner converted to 4 wheel discs manual setup, just left the Single bowl, not sure which disc swap he/she used, but it looks new, not a Granada or older swap.

If not a kit, what all do I need to do and/or get besides a proportioning valve for disc setup and the Dual bowl?

Appreciate the help!

[A/FX]

A double master will bolt right into your existing mounting holes and the plunger rod will also work. The issue is master cylinder bore size. You need to install a cylinder that has a bore compatible with your disc brake system.
You must first determine what size the front and rear calipers have for piston bore size, and if the brake lines are the correct size. If the calipers are Ford OEM parts chances are that some FoMoCo product came with that combination and you just have to duplicate the master cylinder size the factory used.
If you have aftermarket calipers like Baer or Willwood the best thing would be to contact the manufacturer for a recommendation.
Knowing what vehicle the calipers came from does not guarantee what size the bores are, some cars came with different bore sizes depending on the engine size. You need to remove the calipers and measure or use the part number cast into the caliper and cross reference the number. You may also need a proportioning valve in the system to achieve balance between front and rear.
I have always tries to make sure all components are compatible, this eliminates having issues once the system is installed.
Jim

[kyudizky]

Thank you Jim. So to find the bore, do I need to measure the ID of the line going into the caliper to determine the bore size? I don't believe that the calipers have a number cast into them. They do not look OEM.

Please excuse my ignorance. Again the help is much appreciated.

[Rocket989]

Jim’s spot-on...you should measure....it’s a trade-off between pedal travel and pedal effort with the consistent ability to lock the brakes up. Off the cuff, 90-percent of the 4-wheel manual brake setups I’ve seen run a 1” bore MC. On a setup with small enough caliper piston area a 15/16 MIGHT work, but 1-inch is a better bet. Larger than 1-inch (like 1-1/8”) is going to require a LOT of pedal effort.

This is a great write-up with input from Jack Hidley (Maximum Motorsports):
http://forums.corral.net/forums/road-ra ... izing.html

Mine was border-line and I used a 15/16 MC...pretty sure I’ll be swapping to a 1-inch soon...

[lavron]

Obviously mine is still in a box on the shelf, but I bought an all aluminum Lincoln MC (Cardone 13-1518) with a 1" bore, some reason I think it is from the early 80's models but I think a lot of different full sized Fords used the same MC.

I think I ordered it from RockAuto and bought the new and not rebuilt so I could be sure I got the aluminum one (you know weight savings )

I am running Explorer discs on the rear and Speedway metric calipers on the front (probably, most likely, the same as mid 70's full sized GM but have Speedway cast on the case and not a bowtie) my front rotors are probably Granada 11" but were also from Speedway.

I am doing non-power assist 4-wheel disc brakes but I am using a MC off a Lincoln, rear discs off an SUV, and full sized front discs to stop my 2800 pound Comet so I think I will be ok

And I agree on the proportioning valve, I am going with an adjustable one but haven't bought that yet.

See Ya,
Mike

[A/FX]

Thank you Jim. So to find the bore, do I need to measure the ID of the line going into the caliper to determine the bore size? I don't believe that the calipers have a number cast into them. They do not look OEM.

Please excuse my ignorance. Again the help is much appreciated.

Line size does not determine bore size. You might have to remove the caliper to get an accurate measurement. Are the calipers cast iron or aluminum? Do you have a parking brake on the rear? If you can post a picture of each style maybe one of us will recognize what you have.
Jim