SOS MECHANIC CERTIFICATION
COMPREHENSIVE EXAM QUESTIONS AND
CORRECT ANSWERS COMPLETE STUDY
SHEET
●● What should happen to the brake pedal when testing a vacuum power
brake booster?
Answer: Drop slightly and remain firm
●● What is the length of the primary shoe lining when installing brake
shoe linings that are not the same length?
Answer: Smaller and goes towards the front of the car
●● What does a cracked or torn vacuum diaphragm in a brake power
booster cause?
Answer: A hard pedal feel requiring very high pedal effort to stop
●● What is the most likely cause of finding gear lube inside both rear
brake drums on a rear wheel drive vehicle?
Answer: A plugged axle
●● What incorrect service procedure can cause brake lock-up?
Answer: Master cylinder push rod adjusted too long
, ●● How should an ABS system be depressurized?
Answer: Pump the brake pedal at least 25 times with the ignition off
●● What is the most likely cause of dragging rear brakes after new
linings are installed?
Answer: Technician used the parking brake to adjust shoes and the cable
is stuck
●● What should be used when turning brake drums to reduce chatter?
Answer: A dampening strap
●● Which drum brake measurement is NOT necessary?
Answer: Run-out
●● In a 3-channel system, which wheels are on the same circuit?
Answer: Both rear wheels
●● What should be used to test an ABS wheel speed signal?
Answer: AC volts on a digital multimeter
●● What is the key input for the ABS control module?
Answer: Wheel speed sensors
COMPREHENSIVE EXAM QUESTIONS AND
CORRECT ANSWERS COMPLETE STUDY
SHEET
●● What should happen to the brake pedal when testing a vacuum power
brake booster?
Answer: Drop slightly and remain firm
●● What is the length of the primary shoe lining when installing brake
shoe linings that are not the same length?
Answer: Smaller and goes towards the front of the car
●● What does a cracked or torn vacuum diaphragm in a brake power
booster cause?
Answer: A hard pedal feel requiring very high pedal effort to stop
●● What is the most likely cause of finding gear lube inside both rear
brake drums on a rear wheel drive vehicle?
Answer: A plugged axle
●● What incorrect service procedure can cause brake lock-up?
Answer: Master cylinder push rod adjusted too long
, ●● How should an ABS system be depressurized?
Answer: Pump the brake pedal at least 25 times with the ignition off
●● What is the most likely cause of dragging rear brakes after new
linings are installed?
Answer: Technician used the parking brake to adjust shoes and the cable
is stuck
●● What should be used when turning brake drums to reduce chatter?
Answer: A dampening strap
●● Which drum brake measurement is NOT necessary?
Answer: Run-out
●● In a 3-channel system, which wheels are on the same circuit?
Answer: Both rear wheels
●● What should be used to test an ABS wheel speed signal?
Answer: AC volts on a digital multimeter
●● What is the key input for the ABS control module?
Answer: Wheel speed sensors
