Mustang Brake System Tech Guide

One must first understand the basics of the braking system to fully understand where improvements can be most beneficial. The braking components across Mustang generations have varied somewhat, the general basics and core components remain the same.

The brake cylinder assembly, located between the engine and the driver’s side fender, responds to pushing the brake pedal. Above the cylinder assembly is a brake fluid reservoir. The reservoir is usually semi-clear plastic, allowing you to easily monitor the level of fluid inside of it. As you push the pedal, you add pressure to the system. This pressure pushes the pistons in the Mustang's brake calipers, forcing the brake pads to contact the rotors and induce friction. The friction slows your Mustang down.

Brake line pressure can also be altered by the ABS (anti-lock braking systems). The computer utilizes wheel speed sensors located at each wheel. If it sees a difference in wheel speed while braking, the ABS module will trigger solenoids to relieve pressure from the faster spinning wheel. This is why you experience a pulsing sensation if you're hard on the brakes. This helps control your Mustang in extreme braking situations by sacrificing stopping distance.

• Brake Pads
• Rotors
• Calipers
• Brake Lines
• 5-lug Swap (Fox Body Mustangs only)

Brake rotors spin along with the wheels since they're both mounted to the hub via the wheel studs. The brake rotor is high grade steel and will often get a coating of rust very soon after a vehicle is washed or sits in the rain. You’ll see this often with cars at a dealership waiting to be sold. This is nothing to worry about. The brake pads will clean the rust coating off the first time they stop the car.

Surrounding part of the rotor is the brake caliper. On Mustangs, brake pads sit on a pad holder, so you can remove the caliper without removing the brake pads. A piston on the backside of the caliper applies the pressure that squeezes the contact surface of the pads against the brake rotor, bringing your Mustang to a stop.

Drum Brakes: The Mustang hasn’t seen a rear drum brake for many years. However, on older Mustangs such as the Foxbodies, a front disk and rear drum brake setup was common. Instead of utilizing a disk, the drum brake uses a slightly different configuration with the pads positioned inside a steel drum. Disk brakes offer more stopping power, and a rear disk brake conversion is often at the top of the list for those with rear drum brakes. On top of that there are more mechanical parts involved with drum brakes, so routine maintenance is more complicated due to the various springs and clips needed.

Anti-Lock Components: With the introduction of anti-lock brakes, a few additional components were installed at each wheel. These are a toothed speed sensor ring and a speed sensor. The sensor sees the teeth passing by it, knowing that this means the wheel is rotating. When the brakes are applied and the sensor sees that the teeth are no longer moving by the sensor, it knows that particular wheel has locked up. The anti-lock control unit will then pulse the braking power to that particular wheel.

As a side note, the anti-lock braking system is also used by the traction control system. If the sensors indicate the wheels are spinning too fast for the car’s actual speed at the time, power from the engine is restricted until wheelspin is corrected.

Brake Pads: The factory brake pads can often be noisy, as they have a tendency to squeal when applied after they have several thousand miles on it. They also produce a lot of brake dust especially on the front of the car since the front brakes work harder than the rear. While braking performance from the stock pads is much improved in the newer models than in older Mustangs (Fox-Body owners know exactly what I mean), those who push their cars harder will undoubtedly look for more braking power and less braking fade when repeated high speed stops are made.

Factory pads are designed to be softer on purpose. Reason being, believe it or not, the softer pads provide more stopping power sooner than aftermarket pads. The idea is to provide as much stopping power as soon as possible when the brakes are applied suddenly (a situation a daily driven 'Stang might run into). The reason the brakes get upgraded is because of heat. Factory pads are more susceptiple to brake fad; they can't take demanding stops repeatedly without essentially melting.

There are several aftermarket pad options to address these concerns. Carbon-based pads such as the HPS pads offered by Hawk are an example of this. They can take more heat AND provide better emergency braking. They still produce more dust than their ceramic cousins, but this is a good all-rounder option.

If you’re looking for the ultimate in stopping power, and a near complete elimination of brake dust, then ceramic-based pads are your go to. Ceramic pads provide quiet, powerful, and near dust-free operation that is superior to even the best carbon-based pads. When compared to stock replacement pads, high performance pads are a little more costly, but well worth it if you’re looking for improved operation.

Race pads are designed to actually perform better after they warm up (yes, race brakes don't stop the best when cold). After repeated stops, race pads actually bite harder than they would if you've been cruising on the highway for several miles. Needless to say this isn't so handy on the street where you need 100% of your braking randomly and usually suddenly.

There are 3 questions to ask yourself when buying new pads. How hard to you drive/brake? What type of driving do you do? What is this pad going to be used for?

• HPS = Semi all-rounder. Good on the drag strip (one big stopping event) and the street.
• Ceramic = Consider these as upgraded daily driver pads.
• HP Plus = Track/Autocross only. Not suitable for daily street use

Improved pads and rotors will help you enhance your car’s braking ability, but it will only take you so far. If you’re aspiring to move to the next level, conversion kits are the way to achieve this. Think of a conversion kit as a supercharger for your brakes, giving you a substantial increase of 50% or more stopping power. Consider it this way. With a conversion kit you get a bigger surface area so friction can do its job even better. That bigger surface area also allows the brakes to dissipate heat faster so you don't experience brake fade after a stop or two. Conversion kits vary widely in price, depending upon the route you wish to follow. Ford offers the upgrades found on its special edition Cobra and Mach I Mustangs, while renowned companies such as Brembo offer high end conversion kits that offer the ultimate in stopping power.

Should I upgrade my Mustang to a big brake kit? For high performance Mustangs, people tend to work on maximizing the amount of power that their motor creates, but they never consider when you drive faster you will need to stop faster. Upgrading to a “big brake kit” will increase the surface area of your brake pads and rotors, allowing the system to work faster and more efficiently.

Another popular upgrade option is aftermarket brake lines. The factory brake lines are often rubber-based, which tends to flex under heavy use. Aftermarket lines that utilize stainless steel with materials such as Teflon do not flex and expand under the extreme pressures the lines see when the brakes are applied heavily. The result is better braking response, and a much firmer feel at the pedal.

Unless equipped with special brake systems (IE, Brembo), Mustangs primarily come with 3/8 fitting sizes. These can be changed with aftermarket equipment. Few models will have an AN style fitting, mostly -24, but that is not as common.

Brake rotors can be replaced as part of a conversion kit, or on their own. Heat is a byproduct of the friction between the rotor and the brake pads. To enhance braking power, you’ll want to combat the heat. Aftermarket rotor manufacturers do this in a variety of ways. First, they may use a different grade of metal for the rotor. Techniques such as cross-drilling or slots, sometimes a combination of both, also help provide more surface area and better airflow to aid in cooling. Both styles work well, but many times cross-drilled rotors tend to crack under extreme braking conditions.

One thing to keep in mind with aftermarket rotors is maintenance. Some shops will not machine slotted or cross-drilled rotors, which may make maintenance a little more trouble than it would be with stock components. So plan ahead, and make sure you have plans for when that day arrives.

Cooling Kits: You’ll also find various brake cooling kits on the market that use air to cool the brakes. Generally this is performed for the front brakes as they tend to do most of the work. The kits usually use openings that were designed for fog lights, or maybe even part of the openings that direct air to the radiator. Then ductwork channels the air towards the brake rotor and brake pads.

Line Lock/Brake Control​: The drag racing crowd will often use a unique brake accessory to help facilitate heating up the tires during a burnout. Often referred to as a “line lock”, the brake control is used to lock the brakes on the front wheels in place to hold the car still during a burnout. To do this a solenoid is activated by a switch after the brake pedal is pressed. The solenoid holds hydraulic pressure on the front brake lines, in the same manner if you had kept the brake pedal pushed down. The difference is that the rear brakes are not activated. This saves wear and tear on the rear brake components when compared to trying to use the entire braking system to hold the car still for a burnout. It also allows the rear tires to turnover easier and to develop more heat for starting line traction.

If you’re looking for a way to enhance the appearance of your Mustang, but you don’t want to shell out the cash for new brake equipment, caliper paint or caliper covers may be what you’re looking for. The Dupli-Color kits are a good example of caliper paint, although there are many different options available. Some manufacturers even offer caliper paint that is an exact match to the exterior paint of your car.

Another alternative is caliper covers. Caliper covers are made to fit over your existing calipers, giving them the appearance of an aftermarket caliper. They also help reduce the amount of brake dust that reaches the wheel. Installation only takes a few minutes, and therefore even easier and less time consuming than painting your existing calipers.

So what should you go with? For the best results, we recommend the caliper covers. The caliper painting process can be messy and inconsistent. There is also a lot prep work involved. The caliper covers eliminate the mess with an easy bolt-on installation. 

As you can see, there’s a lot more to the braking system than simply a set of pads and rotors. Next time you have a little cash burning a hole in your pocket, remember your car’s braking system. There are several upgrade options that can easily set your car out from the rest of the Mustangs on the road!

Upgrading brake systems can create issues with clearances for wheel fitment. Simply changing rotors and pads will not affect clearance, however changing the brake caliper itself can cause issues. While at first glance it is easy to assume it is in direct relation to the wheel diameter, this is not always true.

The barrel of the wheel itself (how far it goes into the center, from the outer rim towards the center basically) has a large impact on clearances. While a 20" Saleen wheel will not fit certain calipers, an 18" AMR wheel will accommodate all of the calipers. Each wheel is subject to it's own fitment clearances and restrictions.

As for stock wheels, it can vary. If a mustang came stock with a performance pack or track pack, there should not be any clearance issues changing calipers (unless a much larger caliper is being utilized). If it came equipped with the basic level wheels, most likely different wheels will need to be obtained in order to use larger calipers.

When you hit the brakes on your Mustang, the pistons in the caliper push on the brake pads, which causes the brake pads to clamp the rotors. The force of the pads on the rotors creates a lot of friction, and with friction comes heat.

As the pads get hotter and hotter, they lose their ability to keep friction on the rotors, which is called brake fade. To prevent brake fade, you need to increase the thermal capacity of the braking system or increase airflow over the brakes to cool them down.

The best way to increase the thermal capacity of the brake system is to install larger rotors on your Mustang. The larger the rotors, the more material there is available to absorb and dissipate the heat generated during braking. You can not just install larger rotors on your Mustang, because they will interfere with your calipers.

You need to install one of many aftermarket big brake kits such as Brembo or Wilwood. These kits include larger rotors and more powerful calipers. An inexpensive way to upgrade your brakes if you have a V6 to install GT brakes, or if you have a GT you can install Cobra or GT500 brakes.

You will also want to replace your brake fluid as well, since the stock fluid is not really equipped to deal with large amounts of heat, and has a relatively low boiling point compared to performance brake fluid.

Swapping your factory brake pads is a fast and inexpensive way to reduce brake fade. Factory brake pads are designed for longevity, quiet operation, and low dust. While this is good for daily driving, the compound used will overheat higher operating temperature than OEM. The increased braking performance comes at a cost though, the different pad compounds offered are generally more noisy than stock pads until they are warmed up. They also require more heat to work properly, so the first few stops in the morning might squeak and may not bite as hard until the pads are warm.

The final step to controlling your brake fade is to increase the amount of airflow over your brakes to help cool them down faster. You can do this by installing drilled rotors. Installing rotors full of holes may seem counterintuitive since we discussed adding more rotor material to increase thermal capacity, but drilled rotors have more areas for heat to escape.

They allow more air to flow through and around the rotor, allowing it to dissipate quicker. Brake cooling ducts are another popular upgrade for the brake system. These are generally installed on the front of the car with scoops drawing air from the front lower grille.

This air is channeled through tubes that are connected to the back of the dust shield. This extra air will rapidly cool the brakes down, especially when used in conjunction with drilled rotors.

To recap:

• Brake fade is caused by being unable to dissipate heat during/after braking
• Brake fluid is rated by the fluid’s boiling point. If you frequently overheat your brakes, better fluid is a good idea for a simple upgrade
• Larger rotors provide more surface area to absorb and dissipate heat
• Larger rotors will require different calipers, so it’s more cost effective to get an entire big brake kit
• Harder brake compounds can take more heat, but also need a few stops to warm them up. Not always the best choice for a daily driven Mustang
• Drilled and slotted rotors shed heat faster than standard rotors, but eat up brake pads faster

For a Mustang that is daily driven, raced occasionally at the drag strip, or is used for autocross, a good set of pads, drilled rotors and upgraded brake fluid is about all you will need. These upgrades will make for a Mustang that can handle increased braking temperatures with relative ease.

If you plan on road coursing your Mustang, it would be wise to invest in drilled rotors, upgraded pads and fluid, cooling ducts, and a big brake kit. With the full treatment you will be able to keep your Mustangs brakes running cool and fade free for many years to come!