Installing Big Brakes on a Fox-Body
Like many Fox-body owners, straight-line performance is the name of the game. Pumping one of these classic bodies to haul down the quarter is relatively easy, with all the aftermarket support these cars enjoy. They even handle decent out of the box too, but what happens at the long end of the track? God forbid it’s a short track and there isn’t much room for slowing down, the stock brakes are just not quite enough to slow down an 11-second pony.
There are many different kits available for Fox-body Mustangs; each one has its intended market. For our drag-race oriented ’92 Mustang, we wanted a lightweight system that required a minimal amount of modifications and would work with the stock wheels. After some internet research, we came up with the solution, Stainless Steel Brakes Corporation. The SSBC Big Brake front kit offers a cast-iron caliper with a larger piston and beefier, slotted 4-lug rotors that easily fit inside the stock 15” wheel. This kit utilizes the stock mounting hardware, keeping the weight the same. In the rear, SSBC offered up their rear disc kit, which comes complete with rotors, calipers, brackets and brake lines. Everything needed to complete the job. The rear kit actually reduced the overall weight of the car as the heavy drums were eliminated.
The installation for the front kit is simple, basically a brake job, including new rotors and calipers, no special mods, other than the included braided steel brake line. The rear required a little more effort, as the differential had to be drained and the axles removed. Then the caliper mounts and new splash shield bolted on in place of the original backing plates. The nice thing about the rear calipers is the built-in parking brakes. Using a spring-loaded mechanism, the calipers can be actuated to clamp down on the rotors, just like a factory set up. This is an important component, especially considering this Mustang is a shift-it-yourself model. SSBC even supplies brand new cables.
The installation took the better part of a day, with about an hour on the fronts and about 5 hours on the rears. The new pads need to be bedded in before any hard stopping is done. The procedure we use is about 20-30 runs of 10-30-10 braking sessions. This means the car is driven to 30, slowed to 10 or so, accelerated to 30, slowed to 10 and so on. This breaks in the pads and establishes the wear pattern that will forever remain for the life of the pads and rotors. After the 20-30 runs, the car is driven down the highway at a consistent speed with minimal braking. This cools the brakes off. If you don’t do this, the breaks will never be as effective as they could be.
The Mustang was tested before and after using a Vericom VC3000 data-logging performance meter. This extremely accurate computer measures speed, braking time, braking distance, and G-forces. The results were impressive, and certainly justified the $1660 price tag for both kits. The car was put through its paces in a series of 0-30-0 and 0-60-0 tests. Each test was conducted 3 times, then the results were averaged to determine the overall performance. In the 0-30-0 testing, the stock Mustang took 2.82 seconds to stop at 63.35 feet, at an average speed of 31.43 MPH. With the new brakes, the car only required 1.98 seconds to stop within 46.36 feet, at an average speed of 31.53 MPH. This is a difference of 20 feet and 1 second, more than enough to be the difference in an accident and a near miss. The 0-60-0 testing results were similar, with the stock car stopping in 6.37 seconds and 286.51 feet while the modified Mustang stopped in 5.85 seconds at 197.65 feet. That is almost 100 feet shorter than the stock Mustang, which is substantial in the world of fast braking.
In the end, this 11-second 1992 Mustang can now stop just as fast as it can run down the 1320. This not only makes the car safer on the track, but safer on the street as well. In addition, the SSBC kit allowed us to keep the factory look with the stock 4-lug wheels, and even reduced the weight by a few pounds.
1. The Stainless Steel Brakes kits include everything needed to complete the installation. Each kit is separate, front and rear, and both came with master cylinders.
2. With the front of the car lifted up and set on jack stands, the wheels were removed first, and then the calipers.
3. The rotor was also removed, also, and then the spindle was cleaned off. Note the vice-grips on the brake line. This helps keep the air out of the lines.
4. Our kit did not include new bearings, so a quick run to the parts store and we had what we needed. The bearings were packed with Moly grease, and then a new seal was tapped in place.
5. The rotor was slid in place and the castle nut tightened. Don’t forget the cotter pin.
6. The factory rubber brake line was removed from the steel line. Using a line wrench ensures the steel line doesn’t strip.
7. The supplied new braided line was installed on the new caliper. These lines use banjo fittings which require 2 copper washers. 1 washer goes on top and 1 on bottom.
8. The new caliper mounts in the original location and comes with new bolts. We had to ream one of the holes in the outer brake pad, because it was hanging on the bolt. That could cause the brakes to drag, and we don’t want that.
9. The rear brakes start off the same way, with the car supported by jack stands. Our rear shoes were worn quite a bit and we had to back off the adjusters before we could get the drums off.
10. The rear end cover was unbolted and the gear oil was drained. New gear oil smells bad, old gear oil is awful.
11. The axle pin is held in place with a single bolt as noted by the pointer. An 8mm socket and an extension removes this bolt.
12. Then the axle pin slides out. Don’t drop it, it needs to stay smooth. The C-clips can come out once the pin is out.
The axles slide out once the C-clips are out. Keep each axle on the same side they came out.
14. The shoes don’t need to come apart, simply unbolt the backing plates from the axles.
15. These handy little devices were made from the supplied plastic tubing and bleeder tips. We added a small bolt in the end. These will keep the fluid in the lines where it belongs and minimize the air pockets.
16. The supplied caliper mounting bracket bolts to the axle tube using the supplied grade-8 bolts and Nylock nuts. Each side has its own bracket, pay attention to the part numbers. The caliper sits towards the rear of the car.
17. The new backing plates mount to the rear of the bracket. The powder coating filled a couple of the holes and they needed to be chased with a tap.
18. The axles were slid back into the housing and engaged with the carrier.
19. The C-clips were reinstalled in the ends of the axles. Once installed, the axle pin and bolt were reinstalled and the cover placed back over the differential.
20. The rotors were slid over the lugs and the calipers were placed over them. Each rotor is left-hand, right-hand specific. The slots should roll forward, like the picture here:
21. The calipers bolt in from behind using the supplied bolts. The calipers are specific to each side, the bleeder should be on top.
22. The kit came with a hardline extension piece, but we chose to re-route the existing line and plug it directly into the caliper. There is enough flex in the line to accommodate the caliper movement.
23. The kit comes with new E-brake cables. Each cable replaced the stock units and the ends threaded through the caliper E-brake lever.
24. The completed installation looks good.
25. The brakes need to be bled. We gravity bled the caliper by using the tubes we made earlier, without the bolts, and let the air work its way out. The opening must be kept below the bleeder for it to work correctly. Then we bled each caliper under pressure, starting at the rear right caliper and working closer to the master cylinder.
26. There is not much real estate underneath a fox body. We used this little trick to fill up the differential with gear oil. Using a piece of hose, the oil was pumped from outside the car to the rear end. It takes a while, but is easier than the alternative.
27. The VC3000 performance computer attaches to the windshield with pump-action suction pumps. With it leveled and secure, the after testing commenced. The new brakes made significant improvements on the braking performance of the Mustang.
Sources:
Stainless Steel Brakes Corporation
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