A "chirping" noise is heard while the vehicle is moving forward, but stops when the brakes are applied. Technician A says that the noise is likely caused by the disc brake pad wear sensors. Technician B says the noise is likely a wheel bearing because the noise stops when the brakes are applied. Which technician is correct?

A. Technician A only.

B. Technician B only.

C. Both Technicians A and B.

D. Neither Technicians A and B.

A. Technician A only

Explanation:

A "chirping" noise is heard while the vehicle is moving forward, but stops when the brakes are applied. Technician A says that the noise is likely caused by the disc brake pad wear sensors. Technician B says the noise is likely a wheel bearing because the noise stops when the brakes are applied. In the given scenario technician A is correct.

Technician A.

Explanation:

A Brake wear indicator is used to warn the user and/or owner of a vehicle that the brake pad is in need of replacement. By rubbing against the discs, these make a loud screeching sound, providing an audio clue to the driver that the pads have reached their maximum wear limits.

The classic sounds of a bad wheel bearing are cyclic chirping, squealing and/or growling noise. You can also tell that the sound is related to wheel bearings if it changes in proportion to vehicle speed. The sound can get worse with every turn, or it can disappear momentarily.