Brake squeal can occur for several reasons, and sometimes solving it requires trial and error. The most common causes include:

1. Using brake pads with friction levels that are too high for the vehicle (e.g., race pads on light-duty applications).
2. Contaminated brake pads can be caused caused by dust, dirt, glazing, or lubricants.
3. Incomplete contact between the pad and rotor surface.
4. Uneven rotor surfaces or surface rust buildup.
5. Damaged brake hardware such as guide pins, abutment clips, or springs.
6. Some pads require a thin layer of grease between the shim and the backing plate.

This usually comes from either friction material deposits or disc thickness variation (DTV).

Some brake pad materials form an even transfer layer on the disc surface. When this layer becomes uneven, it creates a grab–release effect during braking, which transfers through the steering system and is felt as vibration in the wheel.

DTV refers to uneven rotor wear that causes a similar sensation but with a different root cause.

DTV commonly results from improper brake installation, typically due to unclean hub surfaces or uneven wheel nut torque, often caused by incorrect use of impact wrenches.

Pedal pulsation where the brake pedal moves up and down during braking is almost always caused by hydraulic pressure fluctuations due to DTV (disc thickness variation).

Uneven rotor thickness makes the caliper pistons extend and retract repeatedly, pumping brake fluid back and forth through the hydraulic lines, which is felt as pedal oscillation.

Yes, always clean new rotors before installation. All rotors are coated with an anti-corrosion layer, such as an “En-Shield” coating or a protective oil film.

Use a methanol-based brake cleaner applied to a clean cloth or paper towel. Wipe the friction surfaces and hub face until no residue transfers to the cloth.

Avoid carburettor cleaners, they leave a residue that interferes with proper bedding-in. Also, do not spray aggressive cleaners directly onto painted areas; apply the cleaner to a cloth first to prevent damage to the finish.

Slots help remove brake dust and keep the contact surface between the pad and rotor clean. This maintains consistent friction, prevents glazing, reduces noise, and minimizes overheating.

Slotted rotors are recommended for conditions involving frequent braking or heavy loads, such as commercial vehicles, 4WDs, performance cars, or vehicles used for towing, which generate more debris that the slots help evacuate.

Brake pedal modulation is the technique of controlling how you apply and release the brake pedal when towing heavy loads or descending steep hills.

The idea is to apply the pedal slightly harder than usual for a few seconds, then release it to allow the brakes to cool before pressing again. This cycle helps reduce brake temperature and stress, preventing brake fade or loss of braking performance.