Mechanics begin by asking about:

• What you’re feeling or hearing (e.g., squealing, grinding, pulsing)

• When the issue occurs (e.g., during stops, cold mornings, downhill)

• They usually perform a test drive to replicate the issue.

• Inspect for uneven wear, pad thickness, or caliper damage.

• Check for scoring, rust, or warping on rotors.

• Look at brake lines for leaks or corrosion.

• Examine the brake fluid level and color in the master cylinder.

Pads are measured; if below 3mm, they need replacement.

Rotors are checked for:

• Thickness (using a micrometer)

• Warping (if pedal pulses)

• Scoring or cracking

Mechanics look for sticking calipers (which cause uneven pad wear).

Brake hoses are tested for swelling, cracking, or internal collapse.

Caliper piston movement is checked when the brakes are applied.

For soft or sinking pedals, the master cylinder is checked for internal leaks.

A brake booster vacuum test checks for power assist functionality.

A scan tool is connected to the car’s OBD system.

Mechanics check for stored ABS error codes, faulty wheel speed sensors, or hydraulic unit malfunctions.

Mechanics use test strips or meters to check fluid moisture content and boiling point.

Contaminated or old fluid will lead to a flush recommendation.

A driver complained of brake vibration and noise. The mechanic found warped rotors and unevenly worn pads caused by a stuck caliper. Early detection during a routine inspection could’ve saved the rotor and avoided the extra labor cost.