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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

rear disc upgrade

  • Thread starter Thread starter lxwants12's
  • Start date Start date Aug 18, 2005

lxwants12's

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Sep 22, 2004
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Aug 18, 2005
#1
  • Aug 18, 2005
  • #1
is there a rear disc upgrade available for the 87 to 93 stangs but still keep it 4 lug and fit 15 and 16 inch wheels??
 
A

Andres2882

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Jan 29, 2004
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Aug 18, 2005
#2
  • Aug 18, 2005
  • #2
Turbo coupe rear upgrade from a thunderbird, search for it and it will come. BTW, woot i was first!
 

jrichker

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Aug 18, 2005
#3
  • Aug 18, 2005
  • #3
Been there and done that! With success!

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. 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://www.mustangcentral.net/tech/brake.html for help with the emergency brake - the stock setup tends to lock up and not release properly.

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

crazypete

All my crevices are greased.
Oct 22, 2004
930
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Arlington, MA
Aug 18, 2005
#4
  • Aug 18, 2005
  • #4
Do a search on MC-2300C. It's the old ford 4 lug rear disc conversion kit. It's no longer made anymore but there are a few floating about on ebay and such.

The second thing.....it's REALLY not worth it at all in terms of braking. Nada. I actually brake worse now with the mc-2300c kit in. It's all bling. The fronts do 80% of the braking and you can boost their braking power with a simple 73mm caliper upgrade (drops right in) with some hawk pads and maybe a bigger master cylinder (I love the SVO unit). The disc rears barely do anything at all and unless your kit is complete, I mean right down to the flex hose above the axle, you'll rip your hair out trying to get the conversion done and adapting all the brakelines to eachother...it's really not as trivial as it seems.

Meanwhile, the real braking booster....the calipers and hawk pads made a tremendous difference and took about 20 mins apiece and cost less than $150 for everything. The mc2300C took 2 weekends and a dozen trips to the parts store and cost over $750 altogether to get nothing.

Paint the drums black and spend your money on something worthwile.
 
A

Andres2882

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#5
  • Aug 18, 2005
  • #5
Did you mess with the proportioning valve to make the rear brakes more relevant? Obviously you dont want to lock up the rears ahead of the front brakes, but I wonder if you have them running at full potential?
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
Arlington, MA
Aug 18, 2005
#6
  • Aug 18, 2005
  • #6
I was using the prop valve from an 86 SVO mustang. Those came with disc rears. I dont know if the brakes are adjustable but lets say I did in fact adjust them and their contribution rose to their true potential.....I'd have gained maybe 5% better braking for 750 bucks. Meanwhile the fronts are a cheap and real braking boost for pennies really. Napa stocks the 73mm steel calipers for $19 plus 5 bucks core and the hawk pads are 60 for the front set. Much more bang for the buck.
 

txstang84

15 Year Member
May 21, 2005
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Tuscola, tx
Aug 18, 2005
#7
  • Aug 18, 2005
  • #7
i'm with j on this one, if you choose to piece it together using used components, ck out the site he listed. i did the SVO/MK7 (same parts) rear brake swap...works like a champ on my car. but since i've got a '84, i chose a lincoln town car MC since it still uses SAE fittings.

or-if you don't mind spending $700, SSBC sells their kit which is (if memory serves) all the same components as the t-bird tc...only it fits your stang rear axle.


real quick-has anyone seen that swank new pressure brake bleeder available from jegs? it's like $60, and i guess it hooks up to all the bleeder valves and pushes fluid through the MC at the same time...anyone?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,179
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Massachusetts
Aug 18, 2005
#8
  • Aug 18, 2005
  • #8
crazypete said:
I was using the prop valve from an 86 SVO mustang. Those came with disc rears..
Click to expand...

But SVO's have larger rear disks so the prop valve sends less pressure to the rear to compensate.

You aren't getting the true potential out of your rear brakes unless you gut that prop valve and run an aftermarket unit.
 

txstang84

15 Year Member
May 21, 2005
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Tuscola, tx
Aug 18, 2005
#9
  • Aug 18, 2005
  • #9
Mustang5L5 said:
But SVO's have larger rear disks so the prop valve sends less pressure to the rear to compensate.

You aren't getting the true potential out of your rear brakes unless you gut that prop valve and run an aftermarket unit.
Click to expand...


gut the stock p/v, buy the plug (m-2450-a) install it, pull the coupling for your rear brake line over on the right side of the engine bay, install an adj p/v-did that one on mine
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
Arlington, MA
Aug 19, 2005
#10
  • Aug 19, 2005
  • #10
txstang84 said:
gut the stock p/v, buy the plug (m-2450-a) install it, pull the coupling for your rear brake line over on the right side of the engine bay, install an adj p/v-did that one on mine
Click to expand...

Those rear discs are 10.5's I think. Theyre almost as big as the fronts. I think I matched the PV action to brake size. I'll look into an adjustable.
 
8

87'GTstang

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Feb 16, 2004
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Aug 19, 2005
#11
  • Aug 19, 2005
  • #11
There are more things to disc brakes versus drums that most people seem to leave out all of the time. 1) They don't have the dangerous easy lockup problem drums do that can cause serious skids. 2) They are self-cleaning, no buildup or brake dust trapped let alone stuck between the pad an contact surface. 3) They are self-adjusting - no too tight or too loose of an adjustment. 4) Much easier to maintain/service.

So it's not all just "bling" factor that everyone just calls all of the effort for.
 

txstang84

15 Year Member
May 21, 2005
1,639
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Tuscola, tx
Aug 19, 2005
#12
  • Aug 19, 2005
  • #12
the t-bird rear discs are indeed 10.5"...the stock fronts on a 5.0 are just shy of 11", but like 87'GT mentioned, there are several differences between drum and disc brakes. now unless you are going with the complete exact same setup, i.e. same vehicle weight, weight distrubution, brake type, and size, front and rear, then you really should have an adj p/v installed when swapping from rear drum to disc.

for example, if you took the complete SVO braking system (booster, m/c, p/v, front calipers and rotors, and rear calipers and rotors, then having an adj p/v would be just a redundancy...but could still help you get the most from your brakes

now, with the t-bird brake system, the car-if memory serves-is heavier than a mustang, pulling the complete system off one of them may work satisfactorily, but not optimally due to the difference in vehicle weight and weight distrubution.

in a nutshell, gut your stock pv and plug it, get a new m/c and booster, install an adj p/v, and go from there as outlined by jrichker above
 
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