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Friday, September 11, 2009

Brakes 101

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First the ABS warning light appeared on the dashboard. Then, terrible grinding noises were heard with each push of the brake pedal. It was time for new front brakes for the 2002 Ford Mustang GT. Saturday was spent on this task and it would have gone by faster, but I was there taking photos of EVERYthing, slowing down the process somewhat. But, it was conveniently done for you! After jacking up the car and removing the tire, the brake assembly is visible. There are a couple of bolts to remove so that the caliper can be moved out of the way to check the brake pads and rotor. Make sure not to pinch, break or twist the brake line when moving the caliper out of the way, and it's best to support the caliper during the process, that way the brake line doesn't collapse internally. This would be an ideal time to make sure the line isn't cracked or leaking any brake fluid, and also provides ample opportunity to clean the Wheel Speed Sensors. These are the probes that read a magnetic signal off the sprocket shaped wheel inboard of the Brake assembly. Usually they just accumulate metallic flakes from the rotors, and it's wise to clean them with brake cleaner. Should the WSS get dirty, or be damaged the Electronic Control Unit will display a ABS light on the dash when everything is reassembled. If the WSS is damaged, be sure to replace it. The rotor was worn and there was no meat left on the brake pads. Metal on metal just isn't a sound that anyone wants to hear, plus it's just like welding two pieces of hot metal together. It's just not safe, and very annoying. A quick trip to the auto parts store was needed. In order to get the correct parts, be sure to have the year, make and model of the vehicle. It also doesn't hurt to know the engine size (5.0, 4.6, etc). Taking your vehicle to a dealer, or to a location that performs brake work, can be costly and very expensive. Doing the work yourself, can be rewarding, as well as enlightening. After hearing the selection for brake pads, we settled on the ceramic option. Ceramic pads displace heat a lot faster than any other material available for brakes, and they produce less brake dust, thereby keeping the rims clean and presentable. Sometimes, you can have the rotors "TURNED" so that you can reuse them, other times, they need to replaced altogether. This was one of those instances where they constituted being replaced. Rotors are available standard disc, drilled, slotted, or both. We opted to replace the standard undrilled, and unslotted rotors. Drilled and slotted rotors have increased ventilation in the rotor surface, allowing rapid heat dissipation and more effective cooling. Brakes that do not heat up as quickly provide for faster deceleration, and help eliminate brake fade, and glazing. Depending on your driving style, and application, it's wise to select the best option for your vehicle. Deciding to spice up the brakes a bit, we took a little longer by painting the calipers using a hi-temp caliper paint. Keeping with the black/red theme of the car, the calipers were painted red and can be seen easily behind the rim, adding to the aesthetic appeal of the car. After the paint had dried it was time to reinstall the caliper. Prior to fitting the caliper onto the brake assembly, we had to clamp the pistons so they are fully retracted. Clamping the caliper allows clearance for the new pads, and the new rotor. We used large "C" clamps, and the old brake pad, which give us a surface over the pistons. Once the pistons are fully retracted, discard the old brake pad, and carefully reinstall the caliper. If not installed quickly, the pistons will re-extend, and the process will have to be repeated. Usually, depending on what model Mustang you own, you may encounter a caliper that has more than 2 pistons, this is a High Performance caliper, and they come standard on the Cobra and Shelby. If you have brake drag and the vehicle pulls to one side while driving, this is generally resultant of a stuck piston, or air in the brake line. Replacement calipers are available at your local auto parts store, so take the faulty one with you for comparison, unless your performing a upgrade. Be sure to bleed all the brakes for residual air, regardless of whether or not you have replaced the caliper. Bleeding the brakes requires 2 people, one person to depress the brake pedal and another to loosen the set screw, or bolt on the inboard side of the caliper, normally where the brake line attaches. Once brake fluid comes out consistently, and there are no air bubbles, or pockets, tighten the bolt or screw, and the job is complete.

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