Rear disc brakes in a FOX

There is no MC that will work with no mods due to the 3 port design of the 87-93 Fox cars. You will have to use a 3 to 2 port adapter setup to run any of the rear disc brake MCs. Probably the best combo for you is the 93 Cobra MC & BB since it is the same as the TC rear with V8 front brakes.

If you are running it for a little while, you should have no problem. I changed my MC a couple of months before completing my full 5 lug rear disc conversion since it went out on me. I had no problems, but the brakes were a bit stiffer.

Good luck!

on my Capri I used the SVO MC however I already started with a 2 port MC. I need to upgrade the Powerbooster if i want the brake feel I had before going to 4 wheel disk but I dont think Ill be making that move. The pedal is harder so I can modulate the brakes better.

Been there and done that! With success!

Auto trans 87-88 Tbird Turbo Coupes come with 3.73 gears and manual Turbo Coupes come with 3.55 gears. Cost is
$125-$300 for the rear axle. Add another $100-$200 or so to complete the brake upgrade.

I choose 3.55 since I do more highway driving. Both ratios have 10 5/16" disk brakes with vented rotors as standard equipment.

It takes 2 guys the first day to get the old rear end out and the new one bolted in place. It takes 1 guy another whole day to do the brakes.

You will need a several sets of fittings, I recommend that you get them from Matt90GT's website, 87-93 Mustang 5.0 Brake upgrade pages. Improve your 60-0 times!.
Read Matt's instructions thoroughly, everything you need to know about the brakes is all there. You need to be patient
and follow all the internal links, and there are many of them. You will need 2 fittings in the rear to adapt your old brake
tubing to the TC disk brakes. The fittings go between the steel tube and the caliper brake hose. You will need another set of
fittings to make a 2 port to 3 port adapter. To make life simpler, just buy the kits from Matt. You could piece them
together, but it's not worth the time unless you work at an auto parts store with all the fittings ever made.

You will need to drill the quad shock mounting holes 2” below the holes drilled for the Turbo Coupe mounting points.
The bolts are metric, so don’t loose them or the nuts. A 15/32” drill should be about the right size unless you have access
to metric sized drill bits. Going without quad shocks is not an option unless you have aftermarket parts to soak up the
wheel hop.

You will need a proportioning valve, Summit has one for $42 + shipping. Wilwood 260-8419
You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also has that, about $18. Ford Racing M-2450-A


You will need a new master cylinder, see Matt's site and make you choice. I used a 94-95 Mustang master cylinder.
Note that rebuilt 94-95 Mustang master cylinders do not come with a reservoir. That means a trip to the junkyard and
some more money spent.

Your brake pedal may be very hard and almost impossible to lock up the brakes. I had to replace the front calipers with 73
mm calipers from a 91 Lincoln Mark 7 to get the braking performance up to par. You can use the stock booster if you use
the 73 MM front calipers. The resulting pedal feel is excellent. The pedal isn't too sensitive, it just feels like you have all the
brakes you need.


Bleeding the brakes will require 2 people and some coordinated effort. I don’t recommend using you wife or girlfriend to
pump the pedal – they get offended when you yell at them. I used a homemade power brake bleeder constructed from a
garden sprayer and some fittings from Home Depot. It cost about $25 and was worth every penny.
See how hard is it to bleed brakes? - Mustang Forums at StangNet for details and pictures.

See http://www.mustangcentral.net/tech/brake.html for help with the emergency brake. The red words link to
some very useful photos on how to modify the handle. The stock setup tends to lock up and not release properly.

All in all I have been very pleased with the results.

Identifying a Turbo Coupe rear axle:
1.) Measure the rotors - a TC disk brake uses 10 5/16" vented rotors.
2.) Measure the length of the quad shock mount arm and compare it to the mount on your existing stock axle.
The TC quad shock mount arm is about 8" long if I remember correctly.
3.) Measure the distance between the axle flanges and compare it to stock. The TC rear axle assembly is 3/4" wider per side, or 1 1/2" wider for both sides.

i'm using all 95 v6 parts, master and booster as well. i am getting a pv from this guy on ebay.
he will also have fitting s for conversions if you run into problems

this guy on ebay

93 lx] on my Capri I used the SVO MC however I already started with a 2 port MC. I need to upgrade the Powerbooster if i want the brake feel I had before going to 4 wheel disk but I dont think Ill be making that move. The pedal is harder so I can modulate the brakes better. [/quote] [QUOTE=4turboho said:

and the lines worked fine?

Click to expand...

His car is a pre 87 model, yours is a 91, two different brake systems, so what bolted right in for him will not work for you without modifications. Like Mike and I said, get the 93 Cobra parts and the 3 to 2 port conversion to join the two front lines into one and that is the correct way to the best overall brakes on your car.