Brakes The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

Here’s something new.

93-97 Taurus/sable, 93-00 continental rear calipers are 43mm Vargas.

They swap right onto the sn95 pad bracket. So they work with the GT or cobra setup.

69B76AF1-EA09-477E-B833-937270171C4D.jpeg


Now...what to do with this info
 
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70/30 is the ideal goal.

EDIT: I remove my bias calcs as I found some mistakes. I'll update when I get what I think are accurate numbers

If the rear end of your car was heavy, say with an IRS, then I think the 99-04 Cobra/43mm rear setup may work fine.

As for master cylinder, it's going depend highly on the entire combo. With the ATS Brembo's, a 1" bore MC might be a tad soft with the 43mm rears, but the 1 1/16" bore MC might only be slightly firmer than a factory 94-98 Cobra setup.
 
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Thanks, I am glad I asked. I have a pair of 04 Cobra calipers but have not purchased the rears yet. I will be interested to see your calculations.

According to MM, factory bias is 73/27 with the 38mm rears.

mm brake bias chart.JPG


Changing to 43mm rears and the 11.65" rotor, I get 68% front/32% rear. I believe 70-75% front is considered ideal.

Keep in mind, if you buy the 43mm rears, you still need the SN95 pad hanger bracket. You can't use the Taurus one.

Unsure if these are the Cobra ones.
 
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Changing to 43mm rears and the 11.65" rotor, I get 68% front/32% rear. I believe 70-75% front is considered ideal.

I am glad you mentioned that. Some people may assume the bigger Taurus piston is always best.

Does any one know of a identification chart or guide for determining the caliper years? I frequently see eBay listings stating the calipers are for 94-04 (If you need the "Cobra" on the caliper).

I wonder, is 2.5% worth tracking down the 94-98 calipers?
 
I am glad you mentioned that. Some people may assume the bigger Taurus piston is always best.

Does any one know of a identification chart or guide for determining the caliper years? I frequently see eBay listings stating the calipers are for 94-04 (If you need the "Cobra" on the caliper).

I wonder, is 2.5% worth tracking down the 94-98 calipers?


I run/ran the 99-04 versions on my car. I wouldn't lose sleep over it.

Best way to tell the difference on front cobra calipers is to look at the bores.

The 38mm version has ribbing around the bores (red caliper in photo)
the 40.5mm version has the smooth bores (black in photo)

Most calipers being sold/reman are the 99-04 40.5mm versions.

pic.php_u=11130S5RAi&i=926023.jpg
 
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I currently have a 4 lug, 4 wheel disc system on a '90 GT. This is my system

- 2001 spindles ( I did Mathis k-member mod to relocate control arms and with these spindles, no bump steer kit required)
- '90 T-bird wheel bearing/hub redrilled to 4 lug (same bolt circle)
- Front 11.83" Lincoln LS rotors re-drilled to 4 lug
- Lincoln LS calipers/pads front and rear (I fabbed new brackets to mount calipers from 5/16" steel)
- Rear 11.34" Lincoln LS rotors redrilled to 4 lug
- '94/95 brake booster
- 2001 V6 non-ABS master cylinder and proportioning valve (then can use factory fox brake lines without aftermarket prop valve)
- '94/95 e-brake cables (fabbed front cable mount replicating '94/95 bracket)
- swapped 2001 e-brake handle assembly(had to move rear mount tab forward 1" - fits perfect), this gets proper cable tension spring

Due to rotor size this requires 16" or larger wheels


For 15" wheels change to these parts:

'90 T-bird front rotors - re-drilled(these are same diameter as OEM 94/95 mustang)
- use 94-2004 front caliper brackets (Lincoln calipers will fit)
'94 T-bird rear rotors - re-drilled, slight mod to caliper bracket required


Now the swap to 5-lug:
- use OEM front wheel bearing/hub
- OEM 94-04 rotors and caliper brackets (for 15" rims)
- any other rotor/caliper bracket combo you can think of.
- OEM rear caliper brackets and rotors (for 15" rims)

- my plan is to use OEM '05 rear rotors - 11.83" ( could use Freestar rear rotor for 12.44" rotor)
- fab/modify caliper bracket to suit
- either 12.44" or 13.22" front OEM rotors from a 2014 mustang
- fab/modify caliper bracket to suit
I will need 17s or 18s to clear set up.

By sticking with Lincoln LS calipers I won't need to change MC, prop valve or lines.
 
I started with the rotors. I wanted something a little beefier than the usual 4 lug 4 wheel disc set ups out there. I had a Ford Contour with 4 wheel discs that got me thinking of looking at other models. Not many larger 4 lug set ups out there so I looked at 5x108 lug set ups. I choose that because I could use one of the lugs to assist with alignment for re-drilling.

I found the Lincoln LS/Jaguar S-Type and liked the sizes. Then I decided to use the calipers that came with the discs and went from there.

I use a Contour hub (3 studs removed) with a hub centric ring as my template to re-drill the hubs/rotors. T'bird hubs are within a couple thousandths larger inner diameter on the bearing.

Built whole kit and conversion with drill, grinder, MIG welder and basic hand tools. Worked with what I had.
 
I have been wondering about this for a bit. Does anyone have any details on why the Cobra lettering on the calipers have two different styles. Some calipers the Cobra lettering is recessed in a box and on others the lettering is embossed from the surface of the caliper. It appears to be this way on both the 94-98 and 99-04 piston sizes.

Just a variation in the manufacturing??

In the attached image the Teal calipers are recessed.
calipers.jpg
 
1986 Mustang master cylinder swap - Ford Mustang Forums : Corral.net Mustang Forum

Mustang5L5, based on your advice, I purchased a 1985 Lincoln Town Car master cylinder to replace the stocker on my '86 GT. The new master cylinder came with the pushrod. Do you have experience with this swap? Can I adjust the stock '86 pushrod, or do I have to use the new pushrod?
 
4 Eye SN-95 Cobra Brake Conversion (as performed on my ’86)

79 TO 86 GUYS, THIS ONE IS FOR YOU!

Parts required-

Front:
>94-95 Mustang spindles and hub assemblies (either ABS or regular will work)
>SN-95 ball joints, or a stack of washers to compensate for the long thread section on Fox ball joints *(1)
>13” SN-95 front Cobra brake rotors
>SN-95 rear Cobra calipers, loaded *(2)
>Left/right front brake soft lines for Cobra calipers
>Adapter for passenger side soft to hard brake line *(3)

Rear:
>Fox length 5-lug axles, I used 28 spline Yukon (these are disc brake specific and are hub-centric)
>NRC caliper brackets *(4)
>SN-95 rear Cobra calipers, loaded *(2)
>11.65" rear Cobra brake rotors
>94-95 Mustang rear soft brake lines *(5)
>Hard line to soft line adapter *(3)
>NRC emergency brake cables

Under hood:
>94-95 V6 brake booster *(6)
>85 Lincoln Towncar master cylinder *(7)
>Adapters and hard lines for master cylinder *(3)
>Adjustable brake proportioning valve *(8)
>Stock proportioning valve plug *(8)

Keep in mind that miscellaneous bolts and nuts, like every project, will need replaced or modified as you see fit. Don't use cheap stuff on your brake system, I like to use Grade-8.

Notes:

*(1) Fox ball joints can be reused but have a taller boss that will need to be compensated for with a stack of washers about .250-.375 inch thick so the nut can provide clamping force on the spindle. Get the smallest outer diameter washers you can for clearance with the bottom of the strut. The inner diameter needs to be about 5/8".

*(2) "Loaded" means complete with pads, caliper bracket, pins, etc. Make sure you get the correct banjo bolts that connect the soft lines to the caliper, as some new calipers do not come with new banjo bolts, and these are surprisingly hard to find. I had to buy a set off of discbrakesrus.com. Notice that banjo bolt threads changed over the years so make SURE you have the right set for your calipers.

*(3) I found that the "one size fits all" brake adapters that they sell on various websites often do NOT work for a specific application. Don't buy these blind, take your brake lines into the auto parts store and test fit to find the right adapters for you. With that said, having custom brake lines made at a GOOD brake service station is your best bet over just buying adapters for everything. Cutting, bending, and flaring is better off left to someone who is good at it and gets paid to do it, and most reputable places will do it very cheaply -if not free- so long as you supply the parts and know exactly how the lines need to be shaped.

*(4) Rear NRC (North Race Cars) brackets are very good quality, however you may want to find a set of OE Ford "anti-moan" braces to avoid the inevitable rear brake moan, though these are not needed.

*(5) 94-95 Rear soft lines have a built-in bracket that you can use to mount to your axle with a self-tapping screw.

*(6) You need a larger booster when you use a larger master cylinder to compensate for the bigger brakes. Many different boosters can be used, but find the smallest you possibly can (almost anything is larger than the stock Fox booster), because strut-tower clearance is VERY tight. I found that 4-eye cars have less clearance than aero cars, and the strut tower will need EXTREME clearancing to fit the bigger booster. This was probably the most difficult part of the swap. The mounting holes in the firewall will also need elongated to fit the newer booster. I've heard of people cutting and welding the 4-eye strut tower to fit the booster; I used a hammer to "massage" both the booster and strut tower in my car, and so far I've had no problems with brake assist.

*(7) The 4-eye cars use an SAE thread, double line-style master cylinder. The large-bore '85 Towncar MC is supposed to be the best fit for this style brake swap. Keep in mind that you will likely have to make custom lines to fit between the MC and factory proportioning valve, as there are a few different SAE threads at all the junctions.

*(8) Once the swap is complete, you'll need an adjustable proportioning valve (installed in the brake-line junction on the passenger side firewall) to play with the brake bias between the front and rear wheels. To gut and plug the factory proportioning valve, you can buy one of the specific plugs from FRPP, or you can modify the original cap to act like a plug. I drilled, tapped, and used a screw and nut with brass washers to seal the hole in the original cap because I'm a cheap ass. I've had no leaks so far, but I wouldn't recommend this method to more novice fabricators, because safety is definitely at risk. I'll probably "upgrade" to a real plug in the future, but I thought this was worth mentioning.

*** I'll update this post with more information and pictures in the future. If anyone has any questions or comments, please feel free to PM me. Please also feel free to correct me if I've forgotten anything. ***
Did you replace the struts with a different year..?
 
4 Eye SN-95 Cobra Brake Conversion (as performed on my ’86)

79 TO 86 GUYS, THIS ONE IS FOR YOU!

Parts required-

Front:
>94-95 Mustang spindles and hub assemblies (either ABS or regular will work)
>SN-95 ball joints, or a stack of washers to compensate for the long thread section on Fox ball joints *(1)
>13” SN-95 front Cobra brake rotors
>SN-95 rear Cobra calipers, loaded *(2)
>Left/right front brake soft lines for Cobra calipers
>Adapter for passenger side soft to hard brake line *(3)

Rear:
>Fox length 5-lug axles, I used 28 spline Yukon (these are disc brake specific and are hub-centric)
>NRC caliper brackets *(4)
>SN-95 rear Cobra calipers, loaded *(2)
>11.65" rear Cobra brake rotors
>94-95 Mustang rear soft brake lines *(5)
>Hard line to soft line adapter *(3)
>NRC emergency brake cables

Under hood:
>94-95 V6 brake booster *(6)
>85 Lincoln Towncar master cylinder *(7)
>Adapters and hard lines for master cylinder *(3)
>Adjustable brake proportioning valve *(8)
>Stock proportioning valve plug *(8)

Keep in mind that miscellaneous bolts and nuts, like every project, will need replaced or modified as you see fit. Don't use cheap stuff on your brake system, I like to use Grade-8.

Notes:

*(1) Fox ball joints can be reused but have a taller boss that will need to be compensated for with a stack of washers about .250-.375 inch thick so the nut can provide clamping force on the spindle. Get the smallest outer diameter washers you can for clearance with the bottom of the strut. The inner diameter needs to be about 5/8".

*(2) "Loaded" means complete with pads, caliper bracket, pins, etc. Make sure you get the correct banjo bolts that connect the soft lines to the caliper, as some new calipers do not come with new banjo bolts, and these are surprisingly hard to find. I had to buy a set off of discbrakesrus.com. Notice that banjo bolt threads changed over the years so make SURE you have the right set for your calipers.

*(3) I found that the "one size fits all" brake adapters that they sell on various websites often do NOT work for a specific application. Don't buy these blind, take your brake lines into the auto parts store and test fit to find the right adapters for you. With that said, having custom brake lines made at a GOOD brake service station is your best bet over just buying adapters for everything. Cutting, bending, and flaring is better off left to someone who is good at it and gets paid to do it, and most reputable places will do it very cheaply -if not free- so long as you supply the parts and know exactly how the lines need to be shaped.

*(4) Rear NRC (North Race Cars) brackets are very good quality, however you may want to find a set of OE Ford "anti-moan" braces to avoid the inevitable rear brake moan, though these are not needed.

*(5) 94-95 Rear soft lines have a built-in bracket that you can use to mount to your axle with a self-tapping screw.

*(6) You need a larger booster when you use a larger master cylinder to compensate for the bigger brakes. Many different boosters can be used, but find the smallest you possibly can (almost anything is larger than the stock Fox booster), because strut-tower clearance is VERY tight. I found that 4-eye cars have less clearance than aero cars, and the strut tower will need EXTREME clearancing to fit the bigger booster. This was probably the most difficult part of the swap. The mounting holes in the firewall will also need elongated to fit the newer booster. I've heard of people cutting and welding the 4-eye strut tower to fit the booster; I used a hammer to "massage" both the booster and strut tower in my car, and so far I've had no problems with brake assist.

*(7) The 4-eye cars use an SAE thread, double line-style master cylinder. The large-bore '85 Towncar MC is supposed to be the best fit for this style brake swap. Keep in mind that you will likely have to make custom lines to fit between the MC and factory proportioning valve, as there are a few different SAE threads at all the junctions.

*(8) Once the swap is complete, you'll need an adjustable proportioning valve (installed in the brake-line junction on the passenger side firewall) to play with the brake bias between the front and rear wheels. To gut and plug the factory proportioning valve, you can buy one of the specific plugs from FRPP, or you can modify the original cap to act like a plug. I drilled, tapped, and used a screw and nut with brass washers to seal the hole in the original cap because I'm a cheap ass. I've had no leaks so far, but I wouldn't recommend this method to more novice fabricators, because safety is definitely at risk. I'll probably "upgrade" to a real plug in the future, but I thought this was worth mentioning.

*** I'll update this post with more information and pictures in the future. If anyone has any questions or comments, please feel free to PM me. Please also feel free to correct me if I've forgotten anything. ***
Did you use the factory 86 ebrake cables or replaced those too? If replaced, which ones did you use?
Thanks
 
Drum brake e-brake cable will not work on rear disc brakes. I used cables from a 94/95 car (V6/V8 are the same). You will need to fabricate/swap a front mounting bracket from a rear disc brake car.



IMG_0443.JPG

You will need the front bracket where the cables attach. The second one with the center rivet is not needed, but can help hold the cable from hitting the exhaust or driveshaft. I zip-tied my cables to the factory e-brake cable brackets to keep them tucked up.
 
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Alright i guess i'll start one
First off there are many way to do this, i did this the expensive way
Parts Required
94-95 or 96-98 SN95 Spindles (junk yard $75 a pair)
Cobra Twin Piston PBR Calipers (price varies but i payed 45 each)
MM/Stop tech SS brake lines (check mm website)
13" Parts Master Brand Brake rotors ($32-$48 each)
MM bumpsteer kit (check mm website)
95 SN95 Rear Axle (craigs list 150-600 depending if you can get one with brakes already)
95 Sn95 rear caliper (cobra or GT dont matter they are all the same size $28-$45 dollars)
MM/stoptech rear SS brake lines (check MM website)
95 cobra r master cylinder (new $150)
95 cobra r booster (new $175 reman $85)
Willwood Proportioning valve ($45)
MM 3-2 Port conversion ($35)
Any set of 5 lug rims your heart desires
Typical sizes that fit are 255 for the front and 275 for the rear
now that the parts are out of the way here are the tips

Brake Booster needs to be "fitted" to the car, this involves cutting the lower left hole of the firewall about a 1/2" larger downward and possible massaging of the shock tower

Rear axle, its important for the easiest swap that you locate and axle that has a similar brake line setup as the fox, the SN's had 2 type, one with soft lines at either side of the vehicle, and one with a single soft line in the center and a hardline that run across to both calipers, im not saying the first one wont work but its alot more work as the other is a straight bolt up

E brake cables, there is a possibility that you can re use your factory e brake cables by relocating the brackets so they dont make contact with the wheels, what i did was buy some steel zip ties and attach the brake cable to the calipers and zip tie the loose part of the cable to the lower control arms, then relocate the bracket by drilling 2 holes one for the screw and one for the retaining fold (you'll see what i mean when you get down there) if you go this route you do not need to modify your e brake cable, now this isnt guaranteed to work(worked on my 88 but not my 87)

Now those are the parts and tips i can divulge from doing it myself everything else is basic mechanical knowledge as far as putting everything on the car, just like a brake job, take fox **** off, put SN **** on, its that simple, well it is for me
How did you made the 86 parking cables work wotg the sn95 rear calipers?