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

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
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Massachusetts
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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fox racer v2

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Jun 2, 2019
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Wonder if these would be 'too big' for Cobra front calipers? I just got a pretty decent deal on my rear cobra calipers, so no plans to change that setup. But am curious what 43mm v 38mm in the rear does for MC sizing/bias.
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
8,507
224
Massachusetts
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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Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
8,507
224
Massachusetts
What makes the 94-98 Cobra 70% but the 99-04 Cobra 73%? I thought the calipers were the same throughout those years.
94-98 Cobra calipers use 38mm pistons
99-04 Cobra calipers use 40.5mm pistons.

I removed my numbers...I found some mistakes in my calcs regarding brake pad dimensions. I'll redo shortly
 

FortySix&2

Member
Oct 24, 2001
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Madison Wi
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.
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
8,507
224
Massachusetts
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.
 

FortySix&2

Member
Oct 24, 2001
32
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Madison Wi
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?
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
8,507
224
Massachusetts
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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KRUISR

Member
Apr 16, 2015
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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.
 

KRUISR

Member
Apr 16, 2015
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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.
 

FortySix&2

Member
Oct 24, 2001
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Madison Wi
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
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
8,507
224
Massachusetts
Have seen it both ways as well on both year spans. Have not found any sort of pattern or know the reason
 

Willybill32

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Jul 16, 2019
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Lexington, KY
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?