I Hate When That Happens

Like most things on our vehicles, we do not think of them until they don’t work. This is especially true of our braking systems. Over the years I have been forced to drive vehicles with little or no brakes, that is one scary ride. The automotive brake has been around for as long as the car has been driven. If you think of it, it is quite a task to get a couple thousand pound vehicle to go from 60mph to a dead stop in a matter of seconds. That is where science and engineering meet.

Most modern vehicles use two different types of brakes, the drum brake and the disc brake. The drum brake uses two half moon looking “shoes” that are forced into the inside of a round metal drum. The disc brake uses a rectangular brake “pad”, mounted in a clamping device called a caliper that fits over a round metal disc, when the driver puts their foot on the brake, the caliper clamps down on the disc and this friction will stop the vehicle. Most vehicles these days are equipped with disc brakes on all four wheels. This for a lot of reason, but generally disc brakes work better. Brake engineers sometimes refer to brakes as “heat machines” because they take the energy of motion and transfer it into heat. Then of course the heat has to be dissipated.

The first thing you should know is that all brakes are designed to wear out. The brake pad is made up of a complex compound that will cause just the right amount of friction on the disc rotor to stop the car. It has to do this over and over without overheating and coming apart; it must stop your vehicle quickly, quietly and smoothly, and last a reasonable amount of miles. It is really a tall order. Again brake friction material is designed to wear out.

If you look in a brake parts book you will see many different brake pad numbers for each application. The reason for so many different part numbers has mainly to do with the cost of the materials used. There are cheaper pads, but generally they will not last as long, take longer to stop your vehicle and can be noisier. And on the other end of the scale there are high performance brakes, that are more expensive, for use in taxi cabs and police car applications that are designed for the excessive heat of these uses. So for the most part, you should use the specific type of brake pad that is designed for your vehicle, even if it costs a few more dollars, it is worth it in the long run. It also may be a waste of money to put a taxi cab type of brake on your regular vehicle.

For many years, car manufacture would put a small metal tab on the brake pad. This tab was used as a warning device. When the brake material was worn to a certain point, this tab would ride on the rotor and make a squeaking noise to alert the driver that the brake lining needed service. However, for a number of reasons, the manufacture have not been using this tab. The problem is that there is no advance warning to the driver of service needed. Generally speaking we hear that all of a sudden the brakes are grinding metal to metal. This is unfortunate in my opinion. The only way around this is to have your brakes inspected periodically and keep track of there condition. Because when they are worn out, sometime it is to late and there may be damage done to other parts of the system, mainly the disc rotors. I Hate When That Happens!