S197 Mustang Brake Upgrade: Swapping to Shelby GT500 6-Piston Stopping Power

S197 Mustang Brake Upgrade: Swapping to Shelby GT500 6-Piston Stopping Power

While the stock Mustang braking system has evolved and improved over the course of the S197 run, resulting in a package on the Coyote-powered GT’s that can halt you from speed remarkably quicker than the mediocre 4.6 GT’s package, there is still much room for improvement. Luckily, the GT500’s braking system was also evolving along with its power and speed, and Ford Racing has seen fit to make that package orderable via the M-2300-T kit. The best news of all is that it’s affordable. The whole front and rear swap will only take about four hours on a Saturday afternoon. Of course, our buddy Robin Lawrence had the use of a hoist at Holley, so that did make it all go a little easier. Add a bit more time and maybe one more beer if you’re just using jackstands.

We should be clear: Lawrence is not kind on brakes at all. While most street cars will be fine with the GT package, Lawrence had already found their limits and boiled the fluid more than once. The GT is a driver for him, so he wanted to keep the brakes factory based and easy to find parts for. An upgrade to the 2013-2014 GT500 package from Ford Racing was the ideal solution.

We actually performed this swap a few months back, so not only do we have the ins and outs of the swap, we even have a review from Lawrence’s experience both on the road during daily driving and on the track. Check out the sidebar “Final Thoughts.” He had nothing but good things to report regarding the performance and quality of the parts.

S197 Ford Mustang Gt 15 Inch Brake Swap 02 Stock

1. Here is the 75,000-mile stock 13.2-inch base GT front brake package. The diameter of the rotors is decent, but the calipers don’t deal well with repeated hard braking. Robin Lawrence’s were pretty used up with less than 10 percent of their life remaining, so it was a great time to upgrade.

S197 Ford Mustang Gt 15 Inch Brake Swap 03 Rear Stock

2. These are the stock 11.8-inch rear brakes. For this upgrade, the installation of the rear brake upgrade is actually a whole lot more work than the fronts, so we’re going to start there.

S197 Ford Mustang Gt 15 Inch Brake Swap 04 Brake Cable

3. To begin the disassembly of the rear brakes, the emergency brake cable is easily removed by using a large screwdriver to move the arm then slip the end of the cable from its slot. Then this sheetmetal clip is removed to detach the cable from the caliper assembly.

S197 Ford Mustang Gt 15 Inch Brake Swap 05 Cable Caliper

4. This is the end of the emergency brake cable and the slot where it attaches to the caliper assembly.

S197 Ford Mustang Gt 15 Inch Brake Swap 06 Pins

5. Removing the caliper pins will allow for better access to the caliper bracket bolts. Once the axles are removed we will be able to remove the axle caliper brackets.

S197 Ford Mustang Gt 15 Inch Brake Swap 07 Clips

6. Prior to removing the rotors we need to cut off the clips that hold the rotors in place during shipping from their assembly location. These prevent the rotors from falling off while the assemblies are moved.

S197 Ford Mustang Gt 15 Inch Brake Swap 08 Cut

7. No need to be cautious; since you will not be reusing them, a large screwdriver is used to pry the clip out enough to cut it with a pair of side cutters.

S197 Ford Mustang Gt 15 Inch Brake Swap 09 Axle Remove

8. To remove the rear caliper brackets, we will need to remove the axles. To start, the rear cover is loosened to allow the gear oil to drain. It was about time to change the oil in the diff anyway.

S197 Ford Mustang Gt 15 Inch Brake Swap 10 Remove Cover

9. Once the cover is removed, the bolt that retains the cross pin needs to be removed. The cross pin can then be slid out to allow the axles to be pushed in about 1/2 inch to allow the removal of the C-clips.

S197 Ford Mustang Gt 15 Inch Brake Swap 11 C Clips

10. Using a screwdriver, push the C-clips off of the ends of the axle. Most have a rubber O-ring to hold them in place during assembly.

S197 Ford Mustang Gt 15 Inch Brake Swap 12 Slide Out Axles

11. Once both C-clips are remove you can slide the axles out of the housing.

S197 Ford Mustang Gt 15 Inch Brake Swap 13 Flange

12. With the axles removed you can remove the caliper bracket from the housing flange.

S197 Ford Mustang Gt 15 Inch Brake Swap 14 New Vs Stock

13. Here is the GT500 versus the stock brackets. Note that they are marked “left” and “right” for the proper orientation.

S197 Ford Mustang Gt 15 Inch Brake Swap 15 New Fasteners

14. Don’t attempt to reuse the original bolts. The kit comes with new single-use fasteners that are torque to spec.

S197 Ford Mustang Gt 15 Inch Brake Swap 16 Abs

15. One of the scariest parts of working on brakes is the possibility of damaging the ABS sensors while removing them. Lawrence was able to carefully remove the stock sensors for reuse. The key is to take your time and work them back and forth until they are loose.

S197 Ford Mustang Gt 15 Inch Brake Swap 17 Comparison

16. Here is a side-by-side comparison of the stock rear rotors calipers and the GT500. While stock is 11.8-inch, the GT 500 is 13.8.

S197 Ford Mustang Gt 15 Inch Brake Swap 18 Bolt Down

17. With the new rotors in place, the caliper is bolted down with the supplied hardware.

S197 Ford Mustang Gt 15 Inch Brake Swap 19 Torque

18. The new fasteners were torqued to the factory specs in the instructions provided with the kit. While most of us only use the instructions as a resource when we have a question, Lawrence departed from habit and actually read them before he started the swap. He told us he might start doing that more often!

S197 Ford Mustang Gt 15 Inch Brake Swap 20 Installed

19. Here’s the rear axle, rotor, and caliber assembly installed after reassembly of the rearend. The whole process is straightforward and not difficult; just don’t forget to put new gear oil in the rearend.

S197 Ford Mustang Gt 15 Inch Brake Swap 21 Brembo

20. These are the front bad boys: 14.9-inch rotors with six-piston Brembo calipers. Swapping out the fronts is almost as easy as a normal brake job since the caliper bolts to the same mounting flange as the original brakes.

S197 Ford Mustang Gt 15 Inch Brake Swap 22 Heat Shield

21. After the stock caliper, rotor, and brake line are removed, the new parts are reinstalled. There is a small heat shield that protects the tie rod end to be installed. As with the rears, the kit comes with new single-use fasters. They are torqued to specs provided in the instructions.

S197 Ford Mustang Gt 15 Inch Brake Swap 23 Completed Front

22. Here’s the completed front. It really is that easy; all that was left was to bleed the system since Lawrence also installed new lines in the front.

S197 Ford Mustang Gt 15 Inch Brake Swap 24 Upgraded

23. The massive front rotors and six-piston calipers necessitated an upgrade to 19-inch Boss 302 wheels. Not a bad thing at all since they look great on Lawrence’s black GT.


Final Thoughts

I must admit, I have been very abusive on the brakes since I installed the kit. I drive corners harder and late-brake because I know that I have the hardware that can take the abuse. While this is not a race brake setup, they are certainly a great upgrade from the stock package. At this point I have 35,000 miles on the brake install. I have already replaced the old rubber with a set of Mickey Thompson Sport Comps, which were available in the same OEM sizes as what came on the Boss 302. They have a treadwear rating of 300 and so far they have been excellent in both wet and dry conditions. Best of all, I have yet to find the limits of the brakes and tires. —Robin Lawrence