2002 Nissan Sentra Owner's Manual - Page 185

If the brake pedal goes down farther than normal, it may be due to a lack of adjustment of the rear drum brakes. To adjust, apply the parking brake several times. WARNING See an authorized NISSAN dealer for a brake system check if the brake pedal height does not return to normal. you ever hear an unusually loud noise from the rear drum brakes, have them inspected as soon as possible by an authorized NISSAN dealer. Proper brake inspection intervals should be followed. For more information regarding brake inspections, see the appropriate maintenance schedule information in the ''NISSAN Service and Maintenance Guide''. BRAKE BOOSTER Brake pad wear indicators DI1020M CHECKING BRAKE PEDAL With the engine running, check the distance between the upper surface of the pedal and the metal floor. If it is out of the range shown above, see an authorized NISSAN dealer. The disc brake pads on your vehicle have an audible wear indicator. When a brake pad requires replacement, it makes a high pitched scraping or screeching sound when the vehicle is in motion whether or not the brake pedal is depressed. Have the brakes checked as soon as possible if the wear indicator sound is heard. Under some driving or climate conditions, occasional brake squeak, squeal or other noise may be heard. Occasional brake noise during light to moderate stops is normal and does not affect the function or performance of the brake system. The rear drum brakes (if so equipped) do not have audible wear indicators. Should Check the brake booster function as follows: 1. With the engine off, press and release the brake pedal several times. When brake pedal movement (distance of travel) remains the same from one pedal application to the next, continue on to the next step. 2. While depressing the brake pedal, start the engine. The pedal height should drop a little. 3. With the brake pedal depressed, stop the engine. Keeping the pedal depressed for about 30 seconds, the pedal height should not change. Self-adjusting brakes Your vehicle is equipped with self-adjusting brakes. The front (and rear, if equipped) disc-type brakes self-adjust every time the brake pedal is applied. The rear drum-type brakes also self-adjust every time the brake pedal is applied. 8-30 Maintenance and do-it-yourself