Care of an automobile's brakes is not a casual matter

WARNING: Do not take the brakes of your car for granted. While brake failures are rare with today's advanced dual-breaking systems, still, as the brakes wear, the margin of safety in a regular or panic stop decreases as well.

Not every motorist has the skill to inspect and repair the brakes himself. However, anyone can easily detremine when the brakes need to be serviced.

Disc, drum, or both?

Before you check the brakes or look for brake-service bargains, you need to know what kind of brakes your car has.

Check the owner's manual to determine if your car has 4-wheel disc brakes, drum brakes, or a combination of both.

Most of today's late-model cars are equipped with disc brakes on the front wheels and drum brakes on the rear. A few makes, especially sports cars, have disc brakes on all four wheels. Before 1970, most US cars had drum brakes exclusively.

There's more to brakes than linings

Most of us think that brake service means replacing worn linings alone. But if your car needs a brake overhaul, many more parts are affected. You should know the names of basic brake components so you can better understand what you're paying for when you receive a complete brake job.

The working parts of a drum brake are enclosed in a metal drum attached to the hub of a wheel. Inside, but unattached to the drum, are a pair of curved brake shoes covered with friction linings. These lined shoes press against the rotating drum to cause the wheel to slow down or stop.

The disc brake system consists of a steel disc that is connected to the wheel , and a set of calipers containing pads covered with friction linings. These lined pads close on both sides of the disc to slow or stop the wheel.

furthermore, every brake system is activated by a hydraulic system. When you press down on the brake pedal, brake fluid is forced out of a master cylinder, through the brake lines, to the wheel cylinders which engage the actual brake parts.

Wheel bearings and grease seals are also essential brake parts. Each contributes to smooth braking operation and must be maintained or brake noise and erratic brake operation will occur.

Road-testing your brakes

Many carmakers say brakes should be checked and tested every 12,000 miles. You can do this yourself, but pick a time and place where you can pay close attention to brake performance. This is the best way to uncover common brake problems that may not be apparent in your normal driving activities.

Select a dry, smooth paved street or parking lot that's free of traffic and obstacles. Roll down the windows for good hearing and, at a speed of about 20 mph, apply the brakes firmly for a rapid, nonskidding stop.

* If the pedal depresses to within two inches or less of the floorboard, the linings may be badly worn, brake fluid may be low, or the brake shoes may need adjusting.

Most of today's cars are equipped with self-adjusting brakes.The drum brakes adjust themselves when the brakes are firmly applied while the car is moving in reverse. disc brakes adjust themselves each time the brakes are used. Thus, if the brake pedal goes down farther than normal, try driving backward and forward for a few times while applying the brakes firmly each way. If the pedal does not return to a normal height, the problem is probably not due to maladjustment.

* If you hear a grinding or squeaking noise when the brakes are applied, the brake linings may be worn or they may be covered with grease or oil.

* If you hear a rubbing sound without the brakes being applied, the brakes could be improperly adjusted, a return spring could be broken, or the wheel cylinder or shoe gudes could be binding.

* If the car pulls or sways to one side or the other, or if one wheel grabs when the brakes are applied, it is an indication of improper brake adjustment, grease or hyraulic fluid on the linings, or an out-of-round drum. (Don't be fooled, however. Remember that improper tire inflation, loose or worn wheel bearings, loose steering, or improper front-end alignment can also cause a car to pull.)

Now with the car stopped and the ignition off (ignition on, if the car has power brakes), press the brake pedal and hold it down firmly.

* If the pedal continues to move slowly downward, you could have a master-cylinder problem or a brake-fluid leak somewhere in the hydraulic system.

* If the brake pedal feels spongy, air could be trapped in the system. This is usually caused by a low brake-fluid level. (To correct the problem, the master-cylinder reservoir will have to be filled with fresh fluid of the type and quality specified in the owner's manual. The brakes must also be bled.)

Getting brake service

If you've detected a brake problem, get in touch with your local garage or brake specialist and describe the problem to the mechanic. Most experts will want to pull a wheel to check the brakes before giving an estimate.

Usually, this examination is done free of charge, but inquire first. You don't want to be charged for this service if you decide to take your business elsewhere because the estimate is too high.

Now, if the brakes haven't been replaced for 25,000 to 30,000 miles, the car is due for a major brake overhaul. In this case, compare newspaper ads for the most favorable price for a complete brake job. Always read the ads carefully so as to be sure you're getting quality parts and the most complete service for the advertised price.

While prices vary greatly from shop to shop and discount store to discount store, you should be able to get a sale-priced disc or drum-brake overhaul for between $70 and $100.