Which of these is not a part of a drum brake?
- Shoe
- Lining
- Rotor ✓
- Return spring
Answer: C. Rotor
The rotor is not a part of a drum brake; drum brakes use shoes and linings inside a drum, while a rotor is the disc-shaped part of a disc brake.
Why this is the answer
The handbook separates the two brake types at the wheels. In a drum brake, the shoes and linings sit inside the drum and move outward against it when you brake. A return spring is also listed among the internal S-cam drum brake parts. A rotor, by contrast, is the disc-shaped part used in a disc brake with a caliper and pads. So the rotor is the item that does not belong to a drum brake.
Why the other answers are wrong
- A. Shoe — A brake shoe is named as part of S-cam drum brake hardware and presses outward against the drum, so it is a drum brake part and not the exception.
- B. Lining — A lining is named along with the shoe as part of a drum brake, so it belongs there and is not the exception.
- D. Return spring — A return spring is listed as an internal S-cam drum brake part, so it belongs to a drum brake and is not the exception.
Remember it
Pair them in your mind: drum with shoes and springs, rotor with disc and caliper.