SOS Mechanic
Certification- Brakes
Exam
Section 1: Brake System Fundamentals
1. What is the main function of a vehicle’s braking system?
A. Increase engine power
B. Convert kinetic energy into heat energy
C. Reduce tire wear
D. Improve fuel efficiency
Answer: ✅ B. Convert kinetic energy into heat energy
Explanation: Brakes convert the vehicle’s kinetic energy into heat through friction,
allowing the vehicle to slow down or stop.
2. The friction material of a brake pad is bonded to what component?
A. Rotor
B. Caliper piston
C. Backing plate
D. Wheel cylinder
Answer: ✅ C. Backing plate
Explanation: The brake pad friction material is attached to a metal backing plate,
which supports it during braking.
3. What does DOT stand for in brake fluid?
A. Department of Transportation
B. Density of Tension
C. Degree of Torque
D. Dynamic Operating Temperature
Answer: ✅ A. Department of Transportation
,Explanation: DOT is a federal standard that classifies brake fluids by their boiling
point and performance characteristics.
4. What type of hydraulic brake fluid absorbs moisture from the air?
A. DOT 3
B. DOT 5
C. DOT 5.1
D. Both A and C
Answer: ✅ D. Both A and C
Explanation: DOT 3 and DOT 5.1 are glycol-based and hygroscopic (absorb moisture).
DOT 5 (silicone-based) does not absorb moisture.
5. A vehicle pulls to one side when braking. The most likely cause is:
A. Worn suspension bushings
B. Uneven tire pressure
C. Uneven brake pad wear or sticking caliper
D. Low coolant level
Answer: ✅ C. Uneven brake pad wear or sticking caliper
Explanation: A seized caliper or uneven braking force causes the car to pull to one
side during braking.
Section 2: Hydraulic System & Components
6. What component converts brake pedal pressure into hydraulic pressure?
A. Master cylinder
B. Caliper
C. Brake booster
D. Proportioning valve
Answer: ✅ A. Master cylinder
Explanation: The master cylinder converts mechanical pressure from the pedal into
hydraulic pressure.
, 7. A low brake pedal that pumps up when pressed repeatedly indicates:
A. Air in the brake lines
B. Low tire pressure
C. Bad wheel bearing
D. Warped rotor
Answer: ✅ A. Air in the brake lines
Explanation: Pumping increases pressure temporarily, showing that air is
compressing within the brake lines.
8. What is the function of a proportioning valve?
A. Increases brake line pressure
B. Reduces rear brake pressure to prevent lockup
C. Boosts front brake force
D. Regulates fluid temperature
Answer: ✅ B. Reduces rear brake pressure to prevent lockup
Explanation: The valve prevents rear wheel lock-up under heavy braking conditions.
9. A vacuum brake booster helps reduce:
A. Rotor wear
B. Pedal effort
C. Brake fade
D. Hydraulic pressure
Answer: ✅ B. Pedal effort
Explanation: The booster multiplies pedal force using engine vacuum, reducing driver
effort.
10. When bleeding brakes, the general rule is to start from:
A. The wheel closest to the master cylinder
B. The wheel farthest from the master cylinder
C. The front wheels only
D. The rear wheels only
Answer: ✅ B. The wheel farthest from the master cylinder
Certification- Brakes
Exam
Section 1: Brake System Fundamentals
1. What is the main function of a vehicle’s braking system?
A. Increase engine power
B. Convert kinetic energy into heat energy
C. Reduce tire wear
D. Improve fuel efficiency
Answer: ✅ B. Convert kinetic energy into heat energy
Explanation: Brakes convert the vehicle’s kinetic energy into heat through friction,
allowing the vehicle to slow down or stop.
2. The friction material of a brake pad is bonded to what component?
A. Rotor
B. Caliper piston
C. Backing plate
D. Wheel cylinder
Answer: ✅ C. Backing plate
Explanation: The brake pad friction material is attached to a metal backing plate,
which supports it during braking.
3. What does DOT stand for in brake fluid?
A. Department of Transportation
B. Density of Tension
C. Degree of Torque
D. Dynamic Operating Temperature
Answer: ✅ A. Department of Transportation
,Explanation: DOT is a federal standard that classifies brake fluids by their boiling
point and performance characteristics.
4. What type of hydraulic brake fluid absorbs moisture from the air?
A. DOT 3
B. DOT 5
C. DOT 5.1
D. Both A and C
Answer: ✅ D. Both A and C
Explanation: DOT 3 and DOT 5.1 are glycol-based and hygroscopic (absorb moisture).
DOT 5 (silicone-based) does not absorb moisture.
5. A vehicle pulls to one side when braking. The most likely cause is:
A. Worn suspension bushings
B. Uneven tire pressure
C. Uneven brake pad wear or sticking caliper
D. Low coolant level
Answer: ✅ C. Uneven brake pad wear or sticking caliper
Explanation: A seized caliper or uneven braking force causes the car to pull to one
side during braking.
Section 2: Hydraulic System & Components
6. What component converts brake pedal pressure into hydraulic pressure?
A. Master cylinder
B. Caliper
C. Brake booster
D. Proportioning valve
Answer: ✅ A. Master cylinder
Explanation: The master cylinder converts mechanical pressure from the pedal into
hydraulic pressure.
, 7. A low brake pedal that pumps up when pressed repeatedly indicates:
A. Air in the brake lines
B. Low tire pressure
C. Bad wheel bearing
D. Warped rotor
Answer: ✅ A. Air in the brake lines
Explanation: Pumping increases pressure temporarily, showing that air is
compressing within the brake lines.
8. What is the function of a proportioning valve?
A. Increases brake line pressure
B. Reduces rear brake pressure to prevent lockup
C. Boosts front brake force
D. Regulates fluid temperature
Answer: ✅ B. Reduces rear brake pressure to prevent lockup
Explanation: The valve prevents rear wheel lock-up under heavy braking conditions.
9. A vacuum brake booster helps reduce:
A. Rotor wear
B. Pedal effort
C. Brake fade
D. Hydraulic pressure
Answer: ✅ B. Pedal effort
Explanation: The booster multiplies pedal force using engine vacuum, reducing driver
effort.
10. When bleeding brakes, the general rule is to start from:
A. The wheel closest to the master cylinder
B. The wheel farthest from the master cylinder
C. The front wheels only
D. The rear wheels only
Answer: ✅ B. The wheel farthest from the master cylinder
