2026 GRADED A+ EXAM
SOS Mechanic Certification- Brakes Exam ACTUAL QUESTIONS AND
WELL REVISED ANSWERS - LATEST AND COMPLETE UPDATE WITH
VERIFIED SOLUTIONS 2026\2027
Michigan SOS Brakes Certification
1. A customer complains that the brake pedal slowly sinks to the floor while
stopped at a red light. No external leaks are found. What is the most likely cause?
• A. Worn brake pads.
• B. Leaking master cylinder primary cup.
• C. Air in the brake lines.
• D. Faulty power booster.
• Correct Answer: B
• Rationale: An internal leak in the master cylinder allows fluid to bypass the
piston seals, causing the pedal to drop without losing fluid externally.
2. While performing a brake inspection, a technician finds one brake pad worn
significantly more than the other on the same caliper. What is the cause?
• A. Weak return springs.
• B. Seized caliper slides or pins.
• C. Air in the hydraulic system.
• D. Faulty proportioning valve.
• Correct Answer: B
• Rationale: If the caliper cannot slide freely on its pins, it will apply pressure
unevenly, causing rapid wear on only one pad (usually the inboard pad).
3. Which tool is used to check a brake rotor for "Parallelism" (Thickness
Variation)?
• A. Dial indicator.
,2026 GRADED A+ EXAM
• B. Feeler gauge.
• C. Outside micrometer.
• D. Vernier caliper.
• Correct Answer: C
• Rationale: A micrometer measures thickness at multiple points around the rotor.
A dial indicator is used for "Runout," not thickness variation.
4. A technician is road-testing a vehicle and notices the rear wheels lock up
during a hard stop. Which component is likely defective?
• A. Metering valve.
• B. Proportioning valve.
• C. Pressure differential switch.
• D. Master cylinder.
• Correct Answer: B
• Rationale: The proportioning valve limits pressure to the rear brakes during
heavy braking to prevent rear-wheel lockup.
5. What is the purpose of the "Metering Valve" in a front-disc, rear-drum system?
• A. To delay front brake application until the rear shoes overcome spring tension.
• B. To increase pressure to the front brakes.
• C. To turn on the brake warning light.
• D. To prevent the master cylinder from overflowing.
• Correct Answer: A
• Rationale: Disc brakes apply almost instantly. The metering valve holds off front
pressure so the slower drum brakes can engage at the same time.
6. To test a Vacuum Brake Booster, the technician should:
• A. Pump the pedal with the engine running.
• B. Pump the pedal 4 times (engine off), hold it, then start the engine.
, 2026 GRADED A+ EXAM
• C. Check the fluid level in the master cylinder.
• D. Listen for a whistling sound while driving.
• Correct Answer: B
• Rationale: If the booster is working, the pedal should drop slightly toward the
floor when the engine starts and provides vacuum.
7. When bleeding a brake system, which wheel should usually be bled first?
• A. Left Front.
• B. Right Front.
• C. Left Rear.
• D. Right Rear.
• Correct Answer: D
• Rationale: Standard procedure is to start at the wheel farthest from the master
cylinder to ensure air is pushed through the longest line first.
8. A "spongy" brake pedal is most often caused by:
• A. Worn brake linings.
• B. Overheated drums.
• C. Air trapped in the hydraulic system.
• D. A seized wheel cylinder.
• Correct Answer: C
• Rationale: Air is compressible, whereas brake fluid is not. Trapped air
compresses when the pedal is pushed, creating a soft or spongy feel.
9. What type of signal does a typical passive (two-wire) ABS wheel speed sensor
produce?
• A. DC Voltage.
• B. Digital Square Wave.
• C. AC Voltage.
SOS Mechanic Certification- Brakes Exam ACTUAL QUESTIONS AND
WELL REVISED ANSWERS - LATEST AND COMPLETE UPDATE WITH
VERIFIED SOLUTIONS 2026\2027
Michigan SOS Brakes Certification
1. A customer complains that the brake pedal slowly sinks to the floor while
stopped at a red light. No external leaks are found. What is the most likely cause?
• A. Worn brake pads.
• B. Leaking master cylinder primary cup.
• C. Air in the brake lines.
• D. Faulty power booster.
• Correct Answer: B
• Rationale: An internal leak in the master cylinder allows fluid to bypass the
piston seals, causing the pedal to drop without losing fluid externally.
2. While performing a brake inspection, a technician finds one brake pad worn
significantly more than the other on the same caliper. What is the cause?
• A. Weak return springs.
• B. Seized caliper slides or pins.
• C. Air in the hydraulic system.
• D. Faulty proportioning valve.
• Correct Answer: B
• Rationale: If the caliper cannot slide freely on its pins, it will apply pressure
unevenly, causing rapid wear on only one pad (usually the inboard pad).
3. Which tool is used to check a brake rotor for "Parallelism" (Thickness
Variation)?
• A. Dial indicator.
,2026 GRADED A+ EXAM
• B. Feeler gauge.
• C. Outside micrometer.
• D. Vernier caliper.
• Correct Answer: C
• Rationale: A micrometer measures thickness at multiple points around the rotor.
A dial indicator is used for "Runout," not thickness variation.
4. A technician is road-testing a vehicle and notices the rear wheels lock up
during a hard stop. Which component is likely defective?
• A. Metering valve.
• B. Proportioning valve.
• C. Pressure differential switch.
• D. Master cylinder.
• Correct Answer: B
• Rationale: The proportioning valve limits pressure to the rear brakes during
heavy braking to prevent rear-wheel lockup.
5. What is the purpose of the "Metering Valve" in a front-disc, rear-drum system?
• A. To delay front brake application until the rear shoes overcome spring tension.
• B. To increase pressure to the front brakes.
• C. To turn on the brake warning light.
• D. To prevent the master cylinder from overflowing.
• Correct Answer: A
• Rationale: Disc brakes apply almost instantly. The metering valve holds off front
pressure so the slower drum brakes can engage at the same time.
6. To test a Vacuum Brake Booster, the technician should:
• A. Pump the pedal with the engine running.
• B. Pump the pedal 4 times (engine off), hold it, then start the engine.
, 2026 GRADED A+ EXAM
• C. Check the fluid level in the master cylinder.
• D. Listen for a whistling sound while driving.
• Correct Answer: B
• Rationale: If the booster is working, the pedal should drop slightly toward the
floor when the engine starts and provides vacuum.
7. When bleeding a brake system, which wheel should usually be bled first?
• A. Left Front.
• B. Right Front.
• C. Left Rear.
• D. Right Rear.
• Correct Answer: D
• Rationale: Standard procedure is to start at the wheel farthest from the master
cylinder to ensure air is pushed through the longest line first.
8. A "spongy" brake pedal is most often caused by:
• A. Worn brake linings.
• B. Overheated drums.
• C. Air trapped in the hydraulic system.
• D. A seized wheel cylinder.
• Correct Answer: C
• Rationale: Air is compressible, whereas brake fluid is not. Trapped air
compresses when the pedal is pushed, creating a soft or spongy feel.
9. What type of signal does a typical passive (two-wire) ABS wheel speed sensor
produce?
• A. DC Voltage.
• B. Digital Square Wave.
• C. AC Voltage.
