Eric English
May 1, 2001

Step By Step

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With so many parts and pieces, it’s hard to get them all in one picture. The M-2300-K is a good step beyond an entry-level four-wheel disc upgrade, which might typically include a simple rear disc conversion, better pads, and 73mm front calipers. On the other hand, it’s not the ultimate competition setup, either, falling well short of the gigantic rotors and four- to six-piston calipers found in some racing setups. But no matter. The Cobra brakes are just about perfect for serious street/open-track enthusiasts who appreciate the engineering and serviceability of a production-based system.
Before getting started, Scott Hicks likes to throw all the rotors on a brake lathe to check for excessive runout. As is typical, our discs benefited from a light cleanup cut.
We chose to begin with the underhood and underdash operations first, as they are the most arduous of the tasks. You’ll be disconnecting the master cylinder rod at the brake pedal (underdash) and removing the master cylinder/ power booster assembly, the stock proportioning valve, and the one brake line that must be cut and reflared.
Comparing the old and new power boosters illustrates why the instructions call for “relieving” the aft side of the shock tower for clearance. Interestingly, we’ve talked to several credible enthusiasts who feel the Cobra booster actually gives too much assist, particularly when using more aggressive brake pads, and they therefore prefer using the stock booster. For a how-to article, we felt the need to install the system as Ford intended, but it’s an angle worth considering.
Whacking away on the shock tower with a ball-peen hammer isn’t the most elegant technique, but it does work, and the area will be obscured once everything is back in place. On other installations, Brad Siebold has cut out this area with a plasma cutter, then fabbed a boxed area with sheetmetal for a cleaner, albeit more time-consuming, result. We spent the better part of an hour with our hammer, clearancing a little at a time, fitting and refitting the new booster, until it finally slipped past the obstruction and into place.
The original brake lines are mocked up to the new fixed proportioning valve and master cylinder to check thread compatibility. Brad has found different-year cars sometimes require adapter fittings here, but such was not the case on this ’93—they threaded right in. Here you can see the guts we removed from the fixed valve as per the instructions. With this modification, all brake proportioning now takes place via the supplied Wilwood adjustable proportioning valve.
Here’s the Wilwood valve that plumbs in near the passenger-side hood hinge. The factory has a line connection in this location, so no cutting or flaring is necessary for installation. Many installers will let the valve be supported by the rigid lines, but Brad prefers to quickly fab a support bracket that mounts to one of the hood-hinge bolts. The L-shaped piece was simply bent from a spare piece of aluminum strap, ensuring the metal lines won’t ever fatigue and crack from vibration.
One underhood brake-line (driver’s caliper hard line) modification is required because it now runs into the rear of the fixed prop valve instead of the bottom of the master cylinder. After removing and cutting the brake line, be sure to install the supplied 7/16-inch tube nut before double-flaring the end.
Moving to the front of the car, we’ll direct you to a shop manual or previous issues of 5.0 Mustang & Super Fords for detailed instructions on spring removal. Don’t take any chances on this step as the spring can cause you severe injury if not properly done. Disconnecting the strut, the ball joint, and the tie-rod end, will allow removal of the original spindle.
We’ve moved ahead several steps by reassembling the spring and suspension components with the new SN-95 spindle. The Cobra setup includes new factory dust shields. Those interested in maximum cooling will opt to leave them off—à la Cobra R—but since this ’93 is driven regularly in less-than-perfect weather, we thought the shields were a good idea.
Scott puts the torque on the new hubs to the tune of 250 lb-ft. The average backyard mechanic is unlikely to have the necessary 36mm socket, but it’s something you’ll need to borrow or add to the tool chest. Packing wheel bearings is a thing of the past with these sealed-bearing units.
With the frontend completed, Brad peruses the new components. The installation is extensive, though doable for an enthusiast with good mechanical abilities—and the requisite time. Professional installation will no doubt get you on the road more quickly and should definitely be part of the plan if there are any reservations about turning your own wrenches. Figure a pro install will cost in the neighborhood of $1,000.
As impressive as the front upgrades are, the rears are plenty noteworthy too. Here we compare the wimpy original 9x13/4-inch rear drum with the new 11.65-inch vented rotor and caliper. Can you say goodbye and good riddance?
Though they aren’t included in the kit, we chose to replace the axle bearings while everything was apart. The axle shafts act as the inner race on 8.8 rearends, so matching a new set of bearings with our new five-stud shafts seemed a logical approach—especially with nearly 100,000 miles on the clock. Here, Brad uses a slide hammer to remove the old bearings.
The rear hardware is straightforward factory Ford componentry. Here, the caliper mounting plate is secured with the same hardware as the original drum backing plate.
When it came time to attach the rear caliper brake hoses, we realized there were no existing holes to thread the T40 torx screws into. This small oversight in the instructions was quickly remedied by drilling two 1/4-inch holes in the shock brackets—one for the screw, the other for the locating tang.
Two different sets of emergency-brake cables are included with the M-2300-K—one for the ’87-’92 cars, the other for the unique ’93. Installation was a straightforward replacement, which resulted in perfect e-brake operation. Oddly, our kit lacked a pair of springs, which function to keep the brake cables from contacting the inside of the tires. In fact, the part number had even been scratched from the master parts list. These are necessary items, so Brad modified a pair of throttle-return springs (seen here) to effectively perform the same job. It’s worth mentioning the FRPP instructions mandate a parking-brake hand- lever modification, which eliminates the factory self-adjust feature. The installer is directed to perform a small cut-and-weld job on the assembly, then fit a provided adjustable cable. Since our e-brake was now fully functional, we didn’t see the need to perform this step, and we have a hunch the ’93 setup may make this procedure unnecessary. On the other hand, if time proves the self-adjuster can’t compensate for pad wear or e-brake cable stretch, we can perform the modification later.
Here’s the completed rear-disc assembly. Now it’s time to add brake fluid, bleed the system, check for leaks, and take a test drive. The installation instructions specify a preliminary setting for the adjustable proportioning valve, but after our rotors were seasoned and pads bedded, this application needed considerably more rear brake bias. The need for a high-quality brake fluid should be obvious. We chose to go with Motul 600.
The SN-95 spindles will have thrown your alignment out of whack, so the last step of the installation involves a quality alignment. Instead of your local tire store, seek out a shop that’s familiar with high-performance applications. After asking around, we found our local Ford dealer fit the bill due to technician and fellow enthusiast Brian Holsten. In light of our daily driver status, Brian set us up with a modest alignment featuring 1 degree of negative camber, 3 degrees positive caster, and 1/16-inch toe-in.

The binders on ’94-and-newer Mustang Cobras bite plenty hard and do an effective job of hauling Ford’s top dog down from speed in short order. But what if your budget or preference skews toward the earlier Fox-chassis ’Stangs? The answer is Ford Racing Performance Parts’ M-2300-K brake kit. Specifically designed for swapping Snake brakes on ’87-’93 Mustangs, it can be made to work on the earlier ’79-’86 models and Fox T-birds as well.

So what do you get when that 200-pound box arrives on a pallet at your garage door? A comprehensive kit that includes 13-inch vented rotors/PBR twin-piston aluminum calipers up front, and 11.65-inch vented rotors/single-piston Ford calipers in the rear. Add the geometrically superior SN-95 spindles, the sealed bearing hubs, the rear axles, the power booster, the master cylinder, the brake lines, and the proportioning valves, and you’ve accounted for the major components. A substantial amount of other small parts ensure the result will be a factory-like installation.

Sounds good so far, huh? Considering the vast array of parts that are included, the M-2300-K even qualifies as a great bang for the buck and a hard-to-beat modification for the terribly underbraked Fox cars. That doesn’t mean the setup comes cheap—truly significant brake upgrades never are. A quick perusing of the vendors on these pages reveals pricing in the $1,600-$1,800 range, plus shipping. That’s really only part of the story, however, since the kit necessitates the use of five-lug wheels. If you don’t have the dough to upgrade to new rims and tires, or you’ve already spent some coin on a set of four-lug beauties, you’ll likely want to check other sources for improved braking performance. On the other hand, if you’ve been waiting to do your upgrade and new rolling stock all at once, you’ll consider the beefy Cobra five-lug arrangement a big plus.

We followed along as Brad’s Custom Auto in Seattle, Washington, fitted the Cobra brakes on our bone-stock ’93 LX. Technicians Brad Siebold and Scott Hicks have done numerous M-2300-K installs over the years, and they find the FRPP catalog claim of “virtual bolt-on, requiring only one flared connection” to be fairly true to form.

The subject car was a prime candidate for the upgrade, as not a dime had yet been spent on wheels or brakes. In fact, the front tires and brakes were already on their last legs, which helped lessen the financial blow of all-new components. Unfortunately, this kit is too involved to document every step needed to complete the installation—but hey, even the FRPP instructions fall short of an actual step-by-step bolt-on, recommending access to an SN-95 shop manual to fill in the blanks. So rather than an anal-retentive account, we’ll highlight many of the major procedures, pay particular attention to the tricky steps, and give food for thought to those who recognize the importance of combining plenty of whoa with their 5.0 go.

The result of our day-plus installa-tion is a dramatically changed ’93. Combined with a more aggressive wheel and tire package, the LX now sports a subtly serious image. The big discs and Cobra calipers are clearly visible between the spokes of the ’99-2000 wheels, while the performance improvements are of far greater significance. The car has yet to head to the open track, where its newfound prowess will be put to the test, but we have every reason to believe the results will be well worth the cost and effort.

Horse Sense: Exposing new rotors to extreme heat cycles increases the likelihood of warpage, so go easy on the brakes for a couple of weeks and put some miles on them. This essentially heat treats—or seasons—the discs, which improves durability.