Rear Disc Conversion (What Master Cylinder?)

I would use a proportioning valve for a 4 wheel disc car.
Either that or an aftermarket adjustable one... they are inexpensive.

I don't think the resevior size has anything to do with it.
It all comes down to the proportion of total flow that you do or don't want going to each pair of brakes (frt vs rear).

Dave

Edit:
Check into a Versillies proportioning block, or use the block off a 4 disc Crown Vic/Exploder/Mountaineer/etc...
The later ones though, are probably metric, so you would have to custom make some lines.

brake

If you have a dual reservoir MC you don't have a residual valve. Normally called a check valve on a single bowl MC. So, what are you worrying about?

The best Bang for the Buck MC for 4-wheel disk is the 84 SVO Aluminum MC. You can get it for under $30 rebuilt. That’s what I used on my car when I swapped to 4 wheel discs.
It's light and does the job. You have to make new brake lines because the outlets are on the "wrong" side. Get a Adjustable prop valve and you are good to go. SSBC makes a cool combo distribution and prop valve in one if you want to clean things up a bit.

I used an '86 SVO MC (on a Fox 2.3 booster) in my 66 vert. it's a steel one. It works very well and using a Versailles dist block, I didn't need a prop valve.
The only thing I didn't like is the ports are on the wrong side.

The 4 wheel disc Exploders have the lines on the correct side.
Otherwise they are identical to the Stang master.

You need a disc/disc master cylinder, not a disc/drum master cylinder if that's what you had. Beyond that, Pbum, C6AE and Ratio offer sage advice. My '03 Sporttrac has 4 wheel disc as well.

IIRC, the granada mc has the ports on the same side as the SVO mc


edit: nope, just checked and the granada has the ports on the other side of the mc from the SVO unit, so you will need to make new lines to use the SVO mc.

Volume is very important. As the disc pistons are several times larger than the drum cylinders pistons, as the pads wear it is possable to run out of fluid, even faster if you have multi pistons. Then guess what, they notta work. Select one with large bowls, if yu don't needa de extree fluid, it ain'ta gona hurt.

I would use the adjustable proportioning valve... it gives you infinite ratio adjustment

I used a V-8 Fox booster with a 94/95 Mustang master and a adjustable valve.

A Drum/drum dual reservoir MC will have an RPV (Residual Pressure Valve) installed in both ports. A disc/drum dual reservoir MC will have one RPV in the secondary side port feeding the rear (drum) brakes.

A 4-wheel disc MC will not have any RPVs installed in the MC. If you use a Disc/drum MC on an all-wheel disc setup, the rear discs will drag, causing excessive heat build up and accelerated pad and rotor wear.

I've used two different Ford 4-wheel disc MCs with some disc brake conversions I've done. Here are a couple of examples:

1. Granada disc/drum MC on the left. Lincoln Mk VII/Mustang SVO MC on right; http://www.ultrastang.com/Images/Scanned/June2002/11.jpg

2. Mk VII aluminum 4-wheel disc MC I installed on a 2.3L Fox Mustang brake booster in a '65 coupe; http://www.ultrastang.com/Images/Scanned/June2002/01.jpg


3. SN-95 V6 Mustang 4-wheel disc MC I installed on a 2.3L Fox Mustang brake booster in a '65 fastback; http://img458.imageshack.us/img458/899/65053fd2.jpg

At the time I installed the SN-95 V6 MC in the fastback (2004), I couldn't locate the correct bubble flare fittings to make a direct connection to the MC's ports, so I had to use bubble flare-to-SAE inverted flare port adapters. However, since that time, I located a supplier that I can get the correct ISO bubble flare fittings from to eliminate the adapters in between.

A sample piece of 3/16" brake line I was playing around with: (ISO metric bubble flare fitting on the left end, and a 7/16"-24 SAE inverted flare fitting on the right end of the tube); http://img443.imageshack.us/img443/6972/isobubbleflare003rx0.jpg

--Steve


www.ultrastang.com