Master Cylinder Swap

This Mustang originally had a single reservoir master cylinder with a pressure switch mounted in the MC to activate the brake lights with.
 
In June 1996, when I changed this Mustang over from its stock drums to the Granada front discs, I also changed out the single reservoir MC and replaced it with a dual master cylinder for a '75-'80 model Granada. 
 

 
After the MC swap, there was no longer any provision for the pressure-activated brake light switch. I improvised by installing a Microswitch inside the car that would active the instant the brake pedal was being applied to turn the brake lights on with. 
 
The Granada's proportioning valve was also installed at that time to take care of the discs front/drums rear setup from the drum/drum setup that was previously in place. 
 

As you can see, there's a considerable amount of difference in the physical size of the two master cylinders.
 

Ports exit on the driver's side of the Granada's MC, while the ports on the Mk VII's MC exit on the passenger's side. 
 

Now that the Mustang was being equipped with four-wheel disc brakes, it needed a master cylinder with lots of fluid volume to actuate all four of the large diameter caliper pistons. The Granada's MC is approx. 7" long with a 15/16" bore. The Mk VII's MC is approx. 8 1/8" long with a 1 1/8" bore. Fluid capacity of the Lincoln Mk VII's master cylinder alone is nearly 16 oz. That's lots of fluid capacity! 

 

The Mk VII MC is intended to be installed with a power brake booster but was initially installed on this Mustang without a power brake booster, just to see how it would work. The pedal effort was slightly higher than it was with the smaller bore Granada MC setup, but wasn't what I would call eccessively high in pedal effort.
 

I fabricated all the brake lines from a 60"-long, straight piece of 3/16" brake line tubing. The gravel-guard (the spring-like covering on the tubing), was salvaged from a previous Granada disc brake swap. You can get this covering from most any salvage yard vehicle. Just slide it onto the tubing after the tubing is bent, but BEFORE you put the fittings on the ends of the tubing. 
 

This power brake booster came from a 1992 model 2.3L Mustang LX. I had used this same style brake booster on my '66 fastback in 1996. The only difference is that the booster I used (then) came from a 1980 Mercury Zephyr (same thing as a '78-'80 Ford Fairmont/Fairmont Futura). The Zephyr's booster was identicle to this '92 2.3L Fox Mustang's brake booster, which should be the same in the non-V8 Mustangs from 1979-1993 (except 2.3L convertibles --they are the same (thicker style) as the 5.0L boosters).
 

This booster is very compact at approx. 4¼" thick by 9" in diameter. Pedal effort went down considerably, while braking ability dramatically increased after the installation of this power brake booster! 

Here's a shot of the '92 2.3L Mustang power brake booster, Lincoln Mk VII aluminum master cylinder, Lincoln Mk VII distribution valve and the Wilwood manually-adjustable proportional valve:

 

 

Even with the master cylinder ports exiting on the right (passenger's side), there is still plenty of room between the newly fabricated brake lines and the small-block in this Mustang.
 

 

With the very large Mk VII master cylinder installed on the power brake booster, there's still enough room in front of the master cylinder for me to slide my hand between the MC and the back side of the shock tower! --No problems with interference here!
 

 

A shot of the brake components looking through between the cowl and the back of the hood: