STUDY GUIDE 2025-2026 Most Recent Version
Comprehensive 135 Questions and Verified
Answers Accurate Solutions Already Graded A+
Get it 100% Correct
A COMPRESSOR MAY NOT UNLOAD BECAUSE: - CORRECT ANSWER: A. THE
UNLOADER IS BINDING OR STUCK. (CORRECT AWNSER)
B. THE EXHAUST VALVES ARE LEAKY OR STUCK OPEN.
C. THE DOUBLE CHECK VALVE IS STUCK.
D. THE INLET AIR FILTER IS PLUGGED.
A LIKELY CAUSE OF GRABBING BRAKES ON A DRIVE AXLE WOULD BE: -
CORRECT ANSWER: A. A BAD QUICK RELEASE VALVE. (NOT CORRECT AWNSER)
B. BRAKES ADJUSTED TOO TIGHT. (POSSIBLE CORRECT AWNSER)
C. GREASE OR GEAR LUBE ON LININGS.
D. WEAK SHOE RETURN SPRINGS.
A MECHANIC FINDS GEAR LUBE INSIDE BOTH BRAKE DRUMS ON A DRIVING
AXLE. WHAT IS THE MOST LIKELY CAUSE OF THIS PROBLEM? - CORRECT
ANSWER: A. A BAD PINION SEAL.
B. A PLUGGED AXLE VENT. (CORRECT AWNSER)
C. A BAD WHEEL BEARING.
D. A BAD DIFFERENTIAL CASE SEAL.
A MECHANIC FINDS THAT THE BRAKE LINING IS WORN VERY MUCH NEAR THE
EDGE. WHAT WOULD CAUSE THIS TO HAPPEN? - CORRECT ANSWER: A. BELL
MOUTHED BRAKE DRUMS.
B. WORN-OUT ANCHOR PIN HOLES IN THE BRAKE SHOE.
,C. A BENT BRAKE SHOE WEB.
D. ALL OF THE ABOVE. (CORRECT AWNSER)
A MECHANIC FINDS THAT THE VACUUM HOSE HOOKS UP TO THE POWER
BOOSTER HAS COLLAPSED. WHAT SHOULD THE MECHANIC DO? - CORRECT
ANSWER: A. REPLACE THE HOSE. (POSSIBLE CORRECT AWNSER)
B. REPLACE THE CHECK VALVE.
C.REPLACE THE BOOSTER.
D. ALL OF THE ABOVE. (NOT CORRECT AWNSER)
A MECHANIC HAS REMOVED A BRAKE DRUM AND FOUND THE BRAKE LININGS
SOAKED WITH GREASE. THE BRAKE LININGS SHOULD BE: - CORRECT ANSWER:
A. REPLACED. (CORRECT AWNSER)
B. SANDED TO ROUGHEN UP THE FRICTION SURFACE.
C. DIPPED IN LACQUER THINNER.
D. WASHED WITH DENATURED ALCOHOL.
A MECHANIC IS REPLACING A MASTER CYLINDER. THE PUSH ROD (SEE
BELOW) IS ACCIDENTALLY PULLED OUT AND PART X FALLS OUT OF PLACE.
WHAT WILL CAUSE THIS? - CORRECT ANSWER: A. EXTREME PEDAL
SENSITIVITY.
B. EXCESSIVE PEDAL TRAVEL.
C. EXCESSIVE BRAKE FLUID LOSS.
D. BOTH A AND B. (CORRECT AWNSER)
A PULSATING BRAKE PEDAL IN A HYDRAULIC STSTEM CAN BE CAUSED BY: -
CORRECT ANSWER: A. AN OUT-OF-ROUND DRUM. (CORRECT AWNSER)
B. A DEFECTIVE MASTER CYLINDER.
C. A DEFECTIVE COMBINATION VALVE.
D. A BAD VACUUM BOOSTER.
, AIR BRAKE LINES ARE MSOT OFTEN MADE OF: - CORRECT ANSWER: A. BRASS
AND ALUMINUM.
B. STEELAND NYLON.
C. NYLON AND BRASS.
D. COPPER AND NYLON. (CORRECT AWNSER)
AN AIR OVER HYDRAULIC POWER CLUSTER: - CORRECT ANSWER: A. CONSISTS
OF AN AIR RESERVOIR MOUNTED DIRECTLY OVER A HYDRAULIC RESERVOIR
TO APPLY THE BRAKES IN CASE OF A HYDRAULIC BRAKE FAILURE. (NOT
CORRECT AWNSER)
B. USES A HYDRAUILIC BRAKE APPLICATION IN CASE OF AN AIR FAILURE.
C. USES AIR PRESSURE TO BOOST THE HYDRAULIC PRESSURE IN A BRAKE
SYSTEM. (POSSIBLE CORRECT AWNSER)
D. NONE OF THE ABOVE.
AN ENGINE BRAKE (JACOBS BRAKE) - CORRECT ANSWER: A. IS A SELF-
ENERGIZING SERVO TYPE.
B. IS NORMALLY USED IN PLACE OF A SPRING BRAKE.
C. RESTRICTS THE INTAKE PORT AND CAUSES A BUILD UP OF 30-45 LBS OF
PRESSURE.
D. OPENS THE EXHAUST VALVES NEAR THE TOP OF THE COMPRESSION
STROKE TO RELEASE THE COMPRESSED AIR. (CORRECT AWNSER)
APPROXIMATELY WHAT AIR PRESSURE WILL BE REQUIRED ON A FAIL SAFEOR
SPRING BRAKE STYLE PARKING BRAKE TO HOLD OFF THE SPRING BRAKES? -
CORRECT ANSWER: A. 120-150 PSI.
B. 10 PSI-15 PSI.
C. 60 PSI-80 PSI. (CORRECT AWNSER)
D. 5 PSI.