USPS 943 Exam Questions & Answers 2026 | High-Yield
Automotive Review | Graded A+
1. What is one common cause of a soft brake pedal in a vehicle?
Air in the hydraulic system
Worn brake pads
Low brake fluid level
Faulty brake booster
2. What is wrong during a compression test, if a low compression reading goes
up after a small amount of oil is squirted into a spark plug hole?
worn lifter
burnt intake valve
defective rocker arm
cracked cylinder head
worn piston rings
3. If a mechanic conducts a cylinder leakage test and observes air escaping
through the radiator, what would be the most appropriate next step in
diagnosing the issue?
Replace the piston rings immediately.
Check the fuel injectors for clogs.
Inspect the cylinder head gasket for damage or failure.
Test the ignition system for faults.
4. Describe the role of the PCV system in reducing vehicle emissions.
, The PCV system filters out particulate matter from the exhaust.
The PCV system controls the temperature of the engine.
The PCV system helps to reduce emissions by recirculating
crankcase gases back into the intake manifold for combustion.
The PCV system increases the fuel efficiency of the engine.
5. A mechanic performs a compression test on each of the cylinders of a
gasoline engine. The pressure in one cylinder is much lower than normal, so
the mechanic places a little oil in that cylinder and repeats the test. This time
the pressure reading is close to normal. These results best support which of
the following conclusions?
The cylinder head is cracked.
The intake or exhaust valve is stuck open.
The piston is not advancing fully into the cylinder.
The cylinder or rings are excessively worn.
6. Which component is specifically identified as part of a planetary gear set in
an automatic transmission?
pinion
rotor
modulator
impeller
alternator
7. What is the term used to describe a brake drum that is not perfectly round?
Cracked
Automotive Review | Graded A+
1. What is one common cause of a soft brake pedal in a vehicle?
Air in the hydraulic system
Worn brake pads
Low brake fluid level
Faulty brake booster
2. What is wrong during a compression test, if a low compression reading goes
up after a small amount of oil is squirted into a spark plug hole?
worn lifter
burnt intake valve
defective rocker arm
cracked cylinder head
worn piston rings
3. If a mechanic conducts a cylinder leakage test and observes air escaping
through the radiator, what would be the most appropriate next step in
diagnosing the issue?
Replace the piston rings immediately.
Check the fuel injectors for clogs.
Inspect the cylinder head gasket for damage or failure.
Test the ignition system for faults.
4. Describe the role of the PCV system in reducing vehicle emissions.
, The PCV system filters out particulate matter from the exhaust.
The PCV system controls the temperature of the engine.
The PCV system helps to reduce emissions by recirculating
crankcase gases back into the intake manifold for combustion.
The PCV system increases the fuel efficiency of the engine.
5. A mechanic performs a compression test on each of the cylinders of a
gasoline engine. The pressure in one cylinder is much lower than normal, so
the mechanic places a little oil in that cylinder and repeats the test. This time
the pressure reading is close to normal. These results best support which of
the following conclusions?
The cylinder head is cracked.
The intake or exhaust valve is stuck open.
The piston is not advancing fully into the cylinder.
The cylinder or rings are excessively worn.
6. Which component is specifically identified as part of a planetary gear set in
an automatic transmission?
pinion
rotor
modulator
impeller
alternator
7. What is the term used to describe a brake drum that is not perfectly round?
Cracked
