When to go rear disc?

dubbsix

Member
Oct 18, 2006
347
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Katy,TX
At what point will you all advise that i switch to rear disc brakes?

I plan on building my (now stock) 89 mustang LX to be an occasional drag strip performer, but mostly street driving.
 
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I don't know if there's a point when you're better off to do it or not....maybe if you decide to build a rear end, you might wanna knock it all out at once, or if you decide to do a 5 lug swap. Other than that it's going to benefit you no matter when you do it.
 
Thanks for replying. What is the usually the easiest way to swap out the stock drum rear? do the turbo coupes come with rear disc?


Yeah you can swap the whole rear end in and knock it all out at once, but that rear end is something like 3/4 inch longer.

Check out this site http://sn95brakes.com/5lug.php It's mainly for 5 lug swaps but there's some info about brakes too.
 
Is there away to just add rear discs to the existing rear axle? or do you have swap it out for an entire new unit?

The reason i ask is because i have a complete rear end suspension kit i want to put on, but i dont want to go through the trouble of installing everything if i'll have to eventually unbolt it all to goto rear disc.
 
Link doesnt work... Anyone running a high performance street car that still has rear drum?

If you put a little money into the front brakes and change the pads in the drums, the brakes aren't all that bad unless you wanna go road racing. I plan on doing an SN95 brake swap on the front when i do my 5 lug swap, and then going cheap for a while with Ranger axles in the back until i get the cash for a proper rear disk conversion.
 
Do the 87-88 T-Bird Turbo Coupe rear end swap!

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” 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, http://www.svo73mm.cjb.net/. 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 $40 + shipping.
You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also has that, about $10.


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.

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 http://forums.stangnet.com/showthread.php?p=6143048 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.