Manual brake setup help

[Mtrhd329]

I have 06 crown vic front rotors and calipers. 1.885 bore dual piston caliper 12" diameter rotor, and im running 96 caprice rotors and calipers in the rear. Ill have to get info on those. I have a wilwood prop valve and 3/16" line all around. I will modify my pedal to get the right ratio i just need to know what i would need. I was looking at running the c3 master as its a manual master for disc/disc. Will this work? What would i need for this setup. Thanks!!

[Mtrhd329]

Rear brake info
96 caprice caliper 2.125" bore
Rotor- 11.610 dia

I think this is all the info required. Thanks for looking

[malibudave]

From the factory, a 2006 Crown Victoria came with a 1.0” bore master cylinder. It had twin 48mm (1.89") piston calipers on the front and a single 48mm piston caliper on the rear.

From rockauto.com, the rear piston of a 1996 Caprice is 54mm or 2.13”. This has a piston area that is roughly 20% larger than the Crown Victoria rear caliper.

Usually, going down one bore size for manual brakes is acceptable as long as the piston stroke of the master cylinder is 0.875”- 1.0”. Your pedal ratio should be set up to give you a master cylinder piston stroke of about 1.0” of travel. Usually, the pedal ratio of 6 to 1 will give you this travel.

You should be able to run the 1.0” bore Corvette master cylinder, but this MAY NOT give you the caliper clamping force to stop the car effectively. My opinion would be a 15/16” bore master cylinder is the smallest I would run. This smaller bore size should also handle the extra 20% volume of fluid that the rear calipers need.

[Mtrhd329]

Outstanding. I had thought the rotor size played a factor in there also. Less math. So what kind of vehicle would have a 15/16" bore master? Is that something i can get off the shelf somewhere. I will make sure my pedal is 6:1 and shoot for 1" of travel. Thanks for the quick and informative response!!

[Mtrhd329]

Just heard my buddy has a 7/8" master from a 1980 d50. Suposed to be an oem version of the wilwood? Will this be too small?

[malibudave]

What vehicle is this for?

There are 6 types of stock MOPAR style factory master cylinders.

Smallest ones come from a 1993 Dodge Shadow and other variants. This a K Car master cylinder. Omni, Mini Van, etc. These have 3/8-24 outlets and can be used for disc/disc or disc/drum if they are matched correctly to the size of the calipers. New ones come either in cast iron or aluminum. From the factory they were aluminum. Bore size for rebuilt units can be identified by a number on the top front of the master cylinder. A “1” designates a 21mm bore. An “8” designates a 7/8” bore. A “4” designates a 24mm bore. These designations are NOT on the new, reproduced master cylinders.

Bore sizes
21mm bore - Very rare. If advertised as 21mm bore, you will most likely get a 7/8" bore. This size is usually too small for most manual brake applications.
7/8" bore - Most of these advertised as 7/8" bore but will come as 24mm bore. This is the size used for calipers with front piston area of around 3.9 sq inches (2.5" single piston or 1.77" Dual Piston) and rear calipers with a 48mm piston diameter.
24mm bore - Most common. Should be able to get new or used from auto parts store.

1st gen Dodge Dakota - Come with 1/2-20 outlet for the front brake line (rear port of the master cylinder) and 9/16-20 for the rear brake line (front port of master cylinder).
Bore Size
24mm bore

Mid 80s Dodge Diplomat - Come with 1/2-20 outlet for the front brake line (rear port of the master cylinder) and 9/16-20 for the rear brake line (front port of master cylinder)
Bore Size
1.03" bore - The new ones I have bought have always been 1.125" (1-1/8"). Strange sells there version of this master cylinder in a 1.03" bore.

Mid 80s Dodge Truck - I don't have much experience with these other than they look like Dodge Diplomat unit above. For 99.999% of the applications, this will be too large to use for manual brakes.
Bore Size
1.125" bore - I have never bought. Strange sells there version of this master cylinder in a 1.125" bore.

For the brake setup you are using, I would only go down as small as a 24mm unit which is around the same size as a 15/16” bore master cylinder. 24mm equals to 0.945”. 15/16” equals to 0.938”.

[Mtrhd329]

He giving me a master from a 90s ranger now. He had a d50 dodge truck master which is smaller than the ranger 7/8". I also ordered a 77 malibu 6cyl manual brake booster which is supposed to be 15/16 with 9/16 and 1/2" fittings to try out. Guess i can swap between the free and the one i paid for and see which on i like and maybe return on for some money back.

[Mtrhd329]

Got both masters today and had them side by side. Tanger master was 15/16" and weighed less than a pound veing aluminum and plastic. Malibu master felt like 20 lbs of metal. Took malibu master back and made lines to adapt the ranger master. Hopefully i can get the malibu rod to work on the ranger master. More updates as they happen

[Mtrhd329]

https://static1.pt-content.com/images/pt/2016/07/20160723_192805_zpskiogviol-1.jpg (http://s134.photobucket.com/user/wells_329/media/Mobile%20Uploads/20160723_192805_zpskiogviol.jpg.html)

Mocked up