CORRAL UNIVERSAL RATING SYSTEM:

Difficulty (Easy 1-10 Difficult)		Very Easy
Special Tools (Few 1-10 Many)		None
Price (Cheap 1-10 Expensive)		Cheap
Quality (Poor 1-10 High)		N/A
Improvement (None 1-10 Alot)		Alot
Customer Service (Poor 1-10 Good)		N/A

Potentially the most neglected system on any Mustang is the brake system. Most people spend dozens of hours gapping spark plugs, adjusting fuel pressure, bolting on lots of go fast goodies, and changing the oil; however, hardly anyone bothers to change one of the most important fluids in the car -- the brake fluid.

While most people find them terribly boring, your Mustang's brake system is one of the most important and neglected systems. Sure, a new set of pads and shoes are stuck on every once in a while, and some people even go so far as to order trick dimpled or slotted rotors. Very few people, however, bother to change the brake fluid. This process isn't listed as a regular service item in any manual. It isn't even done by any mechanic who performs brake services on your car unless you specifically ask to have the service done.

"Why is this so important?" you may ask. First we need to understand a few things about how a braking system works, and what brake fluid does. If you'll recall from basic physics and chemistry the Law of Conservation of Energy which states that, "Energy cannot be created or destroyed, but can change its form." When you romp on the gas pedal and accelerate the car you are using a certain amount of energy to get the car up to speed, building up its kinetic energy. So if you've used 250 horsepower to get up to speed in six seconds, you'll need to lose almost that much horsepower to stop.

When you want to slow down you need to get rid of all that kinetic energy. So you press on the brake pedal, fluid is pushed out to the brake pistons in the calipers and they, in turn press the pads against the rotor surface, which creates friction. The force of the Mustang's acceleration turns the brake rotor which is now being clamped by the pads. Remember the Law of Conservation of Energy? ("Energy cannot be created or destroyed, but can change its form.") As the rotor turns and rubs against the pads the friction turns the car's kinetic energy into heat, thus slowing the car down. So basically your brakes are giant heat sinks which serve to dissipate heat.

The more your car weighs and the faster you go, the more energy it takes to get your car off the starting line, and also to stop it. The more energy it takes to stop your car, the more heat that will be generated during the braking process. So if you've got a car full of your friends your brakes will generate a greater amount of heat during braking than if you are travelling alone. It is not uncommon for brakes to get up to several hundred degrees in temperature with moderate to heavy use. Road Race cars often see temperatures high enough to make the brake rotor glow in broad daylight.

What does all this have to do with brake fluid? Remember all that heat that we built up when we hopped on the brakes? A lot of that heat transfers into the braking components of the car, in particular the calipers. Inside the calipers is brake fluid. With several hundred degrees surrounding the caliper, the fluid inside can acutally boil in this miniature oven.

Since brake fluid must put up with these extreme temperatures, it is designed to withstand high boiling points. Most brake fluids don't boil until they reach around 350 deg. Farenheit, some go as high as 550 deg. Farenheit or more! When heated to its boiling point though, brake fluid will boil just like water. When this happens air escapes from the fluid and gets trapped in the brake lines. If you've ever experienced a very spongy brake pedal, chances are you may have boiled your brake fluid. So when you press on the brake you're no longer pressing against brake fluid (which can't be compressed), you're pressing on air (which compresses very easily).

In addition to transferring pressure from your foot to the calipers, brake fluid serves to protect the braking system from corrosion. Water vapor in the air can mix with the brake fluid by entering in through any number of places: the reservior cap, bleed screws, hose junctions, pistons, etc. Water inside the braking system can wreak havoc, it can corrode and rust brake lines and calipers rendering them inoperable or ineffective at best. For this reason brake fluid is hygroscopic, meaning that it absorbs water. It does this to help keep water away from the metal parts of the brake system. By doing this it keeps the components from rusting.

The idea behind bleeding the brakes is to remove any air and old fluid from the system. Good brake fluid should be a "honey" color and should have the consistency of light oil. It should NOT be "watery" or look like coffee! Generally the more water the fluid has absorbed the more "coffee-like" its appearance.

First you'll want to pick up a few items. If you are planning on doing this yourself, you'll need a one man brake bleeder kit, which you can get from your local auto parts store for about $10-20. If you've got help you'll need some clear plastic tubing, about 3' should be more than enough. It will need to be about 1/8" inside diameter, big enough to fit on to the bleeder screw nipples, but tight enough to keep fluid and air out.

Next you'll need lots of brake fluid. Ford Heavy Duty Brake Fluid is HIGHLY recommended and you can get it from any Ford parts counter. We've used it in race cars and in street cars, it has a high boiling point, provides relatively long life before it needs to be changed, and best of all it is CHEAP. Performance is about as good as some of the more expensive racing brake fluids and you can get this for about $5/container at the dealership. Get at least three.

You'll also want some kind of container to drain the old fluid into. 1 Liter soda bottles work great because they have a screw cap. Get a couple of these. PLEASE DISPOSE OF USED BRAKE FLUID PROPERLY!

Make sure that when you're doing this that YOU DO NOT GET BRAKE FLUID ON THE PAINT!!!! It will eat the paint off your car! Also be sure not to let fluid get on the brake pads.

First, put the car up on jack stands on a LEVEL surface.

Remove all the wheels.

The order of bleeding should go like this:

• Always start bleeding from the wheel that is FARTHEST away from the master cylinder. On a Mustang this is the Passenger side rear wheel.
• Next, do the Driver's side rear wheel
• Now do the Passenger side front wheel
• Finally bleed the Driver's side front wheel.