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Automotive Servicing NC II study materials
Automotive Servicing NC II study resources

Automotive Servicing NC II practice questions

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Question 1Workplace communication, safety, and housekeeping

In an automotive workshop, which personal protective equipment is most important when grinding or cutting metal with a portable grinder?

  1. Cloth gloves
  2. Rubber boots
  3. Dust mask only
  4. Face shield with safety glasses underneath Correct answer.

Explanation

Grinding and cutting throw high-speed metal fragments and sparks toward the face, so a face shield worn over safety glasses gives the required eye and face protection. Standard shop gloves, boots, and a dust mask do not stop flying particles from striking the eyes.

Question 2Workplace communication, safety, and housekeeping

A technician must lift a transmission from the floor to a bench. Which practice follows correct manual handling?

  1. Hold the load at arm's length for better balance
  2. Keep the load close, bend the knees, and lift with the legs Correct answer.
  3. Lift quickly with a jerking motion to save effort
  4. Bend at the waist and twist while lifting

Explanation

Safe manual handling keeps the load close to the body, uses the leg muscles, and keeps the back straight to reduce strain on the spine. Twisting, reaching out, or jerking increases the risk of back injury.

Question 3Workplace communication, safety, and housekeeping

After finishing a job, a technician spills engine oil on the workshop floor. What is the correct immediate action?

  1. Contain and absorb the spill, then dispose of the waste properly Correct answer.
  2. Wash it into the floor drain with water
  3. Cover it with a cardboard sheet and continue working
  4. Leave it to dry and sweep it later

Explanation

Oil spills must be contained and absorbed promptly to prevent slips and to stop oil reaching drains or soil. The used absorbent is then disposed of according to the workshop's waste rules. Washing oil into a drain causes pollution and is prohibited.

Question 4Workplace communication, safety, and housekeeping

Which fire extinguisher class is suitable for a fuel or oil fire in an automotive workshop?

  1. Class D metal-powder extinguisher
  2. Class B foam or dry chemical extinguisher Correct answer.
  3. Class A water extinguisher
  4. Class C only carbon dioxide for electrical fires

Explanation

Flammable liquids such as petrol, diesel, and oil are Class B fires, and foam or dry chemical extinguishers are designed to smother them. Water must never be used because it spreads burning liquid.

Question 5Workplace communication, safety, and housekeeping

What is the main purpose of the 5S method in an automotive service bay?

  1. To increase engine power output
  2. To organize the workplace for safety and efficiency Correct answer.
  3. To shorten the warranty period
  4. To reduce the price of spare parts

Explanation

5S (sort, set in order, shine, standardize, sustain) organizes tools and the work area so hazards are removed and time is not wasted searching for items. It does not affect engine output, parts pricing, or warranty terms.

Question 6Workplace communication, safety, and housekeeping

Before starting work under a vehicle raised on a two-post hoist, what is the essential safety check?

  1. Verify the tires are inflated to maximum pressure
  2. Confirm the lift arms are correctly positioned at the vehicle's lifting points and the hoist is locked Correct answer.
  3. Make sure the workshop door is closed
  4. Check that the radio is switched off

Explanation

The lift arms must sit at the manufacturer's lifting points and the mechanical locks must engage so the vehicle cannot fall. These are the checks that directly prevent a hoist collapse or vehicle drop.

Question 7Workplace communication, safety, and housekeeping

A customer phones the shop and says their car makes a noise only when turning. Which response best applies effective workplace communication?

  1. Quote a final repair price immediately
  2. Tell the customer to call back when the noise is constant
  3. Ask specific questions about when the noise occurs, its location, and any recent repairs, and record the answers Correct answer.
  4. Say the problem cannot be diagnosed over the phone and end the call

Explanation

Effective service communication gathers structured information: the conditions, location, and history of the complaint, then records it for the technician. This helps reproduce the fault and plan the diagnosis. Dismissing the call or quoting a final price without inspection is unprofessional.

Question 8Workplace communication, safety, and housekeeping

A technician finds a serious brake defect that makes the vehicle unsafe to release. What is the correct action?

  1. Release the vehicle and advise the owner to return soon
  2. Inform the customer clearly of the defect and safety risk, and document the advice before releasing the vehicle Correct answer.
  3. Note the defect only in the internal file and say nothing
  4. Repair it quietly and add the cost to the invoice without informing the owner

Explanation

When a defect affects safe operation, the technician has a duty to inform the customer of the risk in clear terms and record that the advice was given. This protects the customer and the workshop. Silent repairs or silence about a hazard are unacceptable.

Question 9Workplace communication, safety, and housekeeping

Which document authorizes a technician to carry out additional repairs beyond the original job order?

  1. The parts delivery receipt
  2. A revised job order or repair order approved by the customer Correct answer.
  3. The technician's own notebook entry
  4. A verbal remark from another technician

Explanation

Extra work must be authorized in writing, usually through a revised job order or repair order signed or approved by the customer. This prevents billing disputes and confirms consent. Verbal remarks, receipts, and personal notes do not authorize work.

Question 10Workplace communication, safety, and housekeeping

During a road test, the customer's vehicle is damaged in a minor collision. Which sequence of actions is most appropriate?

  1. Report it to the supervisor immediately, record the incident, and inform the customer honestly Correct answer.
  2. Blame the traffic and continue the job
  3. Wait until the customer notices the damage
  4. Repair it quietly and say nothing to avoid conflict

Explanation

An incident must be reported at once to the supervisor, documented, and disclosed honestly to the customer. Early reporting allows insurance and repair arrangements to be made properly. Concealment or blame-shifting destroys trust and may breach policy.

Question 11Workplace communication, safety, and housekeeping

Which practice best prevents the spread of contamination when handling used oil and coolant?

  1. Pour both into the same open drum for convenience
  2. Store them in labeled, separate containers and follow the waste disposal procedure Correct answer.
  3. Mix them with detergent and flush to the drain
  4. Pour them onto gravel behind the shop

Explanation

Used oil and coolant are different waste streams and must be kept in clearly labeled, separate containers for proper recycling or disposal. Mixing them or dumping them contaminates the environment and breaks waste regulations.

Question 12Workplace communication, safety, and housekeeping

A technician must use a hydraulic press to remove a bearing. Which precaution is most important before applying pressure?

  1. Leave the workpiece unsecured so it can shift freely
  2. Remove all guards for a better view
  3. Stand directly in line with the press ram to watch closely
  4. Check the setup is aligned and use a guard or stand to the side Correct answer.

Explanation

Hydraulic presses store large forces, and a misaligned or unsecured workpiece can fly out under load. The setup must be aligned and secure, and the operator should stand clear of the line of force behind a guard.

Question 13Workplace communication, safety, and housekeeping

Which action correctly applies the 'set in order' step of 5S in a tool cabinet?

  1. Store all tools together in one deep drawer
  2. Lock the cabinet and let the supervisor hold the key
  3. Assign a labeled place for each tool and return it after use Correct answer.
  4. Keep only the tools used last week

Explanation

'Set in order' means every item has a designated, labeled location so it can be found and returned quickly. This reduces search time and lost tools. Mixing tools in one drawer or locking them away defeats the purpose.

Question 14Workplace communication, safety, and housekeeping

A workshop has several technicians using the same torque wrench. What is the best way to ensure it stays accurate?

  1. Store it fully wound at maximum setting
  2. Use it as a hammer when needed
  3. Return it to zero after use and send it for periodic calibration with records Correct answer.
  4. Rely on the technician's feel

Explanation

Torque wrenches should be returned to the lowest setting after use and checked against a calibration standard at scheduled intervals, with records kept. This keeps readings trustworthy for critical fasteners.

Question 15Workplace communication, safety, and housekeeping

Which is the correct way to communicate a technical finding to a customer who has no mechanical background?

  1. Give only the part number and price
  2. Explain the fault in plain language, show the worn part, and state the consequence of not repairing it Correct answer.
  3. Tell the customer it is complicated and they would not understand
  4. Use the same technical jargon used between technicians

Explanation

Clear communication means translating technical findings into plain language, using the removed part as evidence, and explaining the consequence of deferring repair. This supports an informed decision. Jargon or dismissive remarks leave the customer unable to decide.

Question 16Workplace communication, safety, and housekeeping

A workshop stores oxygen and acetylene cylinders for welding. Which arrangement meets safe storage practice?

  1. Keep them upright, secured, separated, with flashback arrestors fitted and caps on when not in use Correct answer.
  2. Keep the acetylene cylinder on its side with the valve open
  3. Store them near the paint mixing area for convenience
  4. Store them lying together in a locked metal cabinet

Explanation

Gas cylinders must be stored upright and secured, with oxygen and fuel gas separated, valve protection caps fitted, and flashback arrestors on the lines. This reduces the risk of leaks, falls, and flashback explosions.

Question 17Workplace communication, safety, and housekeeping

A technician is asked to sign off a repair that was not actually completed because a colleague is absent. What is the correct professional response?

  1. Refuse to sign, and report the discrepancy to the supervisor Correct answer.
  2. Sign it but write a private note
  3. Ask another trainee to sign instead
  4. Sign it to keep the workflow moving

Explanation

Signing off work that was not performed falsifies the service record and can release an unsafe vehicle. The technician must refuse and escalate the discrepancy to the supervisor so the record stays truthful.

Question 18Workplace communication, safety, and housekeeping

A workshop notice states that a job must be finished in half the normal time. What is the best professional response from the technician?

  1. Raise the concern with the supervisor, explain the safety-critical steps that cannot be rushed, and agree a realistic plan Correct answer.
  2. Skip the torque check to save time
  3. Ignore the notice and finish whenever convenient
  4. Work faster by omitting the final inspection

Explanation

When time pressure conflicts with safety-critical procedures, the technician should communicate the concern, identify which steps cannot be shortened, and agree a realistic schedule. Safety checks such as torque and final inspection must never be skipped.

Question 19Workplace communication, safety, and housekeeping

A technician notices that a compressed air line has a small leak and the hose shows cracking. What is the correct analysis and action?

  1. Tag the equipment out of service, isolate the air supply, and report it for replacement Correct answer.
  2. Tape the hose and continue using it at full pressure
  3. Point the leak toward a coworker to check the airflow
  4. Increase the pressure to compensate for the leak

Explanation

A cracked air hose under pressure can burst and cause serious injury, so the equipment must be isolated, tagged out, and reported for replacement. Taping or raising pressure increases the risk, and compressed air must never be directed at people.

Question 20Workplace communication, safety, and housekeeping

A workshop must dispose of used lead-acid batteries and worn brake pads. Which approach reflects correct environmental and safety practice?

  1. Place them in the general waste bin
  2. Bury them at the back of the lot
  3. Store them in labeled containers and send them to an approved recycler or hazardous-waste handler Correct answer.
  4. Burn the pads to reduce volume

Explanation

Lead-acid batteries and brake pads contain hazardous materials, so they must be segregated in labeled containers and passed to an approved recycler or hazardous-waste handler. General disposal, burial, or burning releases toxic substances into the environment.

Question 21Use of hand tools, measuring instruments, and test equipment

A technician needs to loosen a 14 mm hex bolt on a brake caliper. Which tool provides the correct fit and is designed for this fastener?

  1. A 14 mm combination wrench used on the box end Correct answer.
  2. An adjustable wrench set wide open
  3. A 14 mm open-end wrench
  4. A 12 mm box-end wrench

Explanation

A box-end wrench fully surrounds the hex head and contacts all six flats, which gives the best grip and lowest risk of rounding a tight caliper bolt. The box end must match the fastener size exactly, so a 14 mm box end is the correct choice for a 14 mm bolt.

Question 22Use of hand tools, measuring instruments, and test equipment

Which measuring instrument is the standard choice for checking the outside diameter of a valve stem to within 0.01 mm?

  1. A dial indicator on a magnetic base
  2. A vernier caliper Correct answer.
  3. A steel rule
  4. A feeler gauge

Explanation

A vernier caliper with 0.01 mm resolution can measure outside diameter directly across the jaws and is the usual shop instrument for this check. A steel rule is far too coarse, a feeler gauge measures gaps, and a dial indicator measures movement rather than diameter.

Question 23Use of hand tools, measuring instruments, and test equipment

Before using a micrometer screw gauge, the technician closes the anvils and finds the thimble zero does not line up with the sleeve datum line. What is the correct action?

  1. Open the anvils slightly so the error disappears
  2. Discard the micrometer as unserviceable
  3. Zero the micrometer using its adjustment feature or record the error and correct readings Correct answer.
  4. Add the error to every reading taken

Explanation

A micrometer must read zero with the anvils closed and clean; if it does not, the instrument is adjusted to zero or the zero error is recorded and applied to readings. Ignoring the error would make every measurement wrong by the same amount.

Question 24Use of hand tools, measuring instruments, and test equipment

A torque wrench is stored with its scale set to 90 N·m after the job is finished. Why is this a problem?

  1. The handle grip will crack
  2. The ratchet direction reverses
  3. The scale markings fade
  4. The internal spring stays compressed and the calibration drifts Correct answer.

Explanation

A click-type torque wrench relies on an internal spring, and leaving it loaded keeps the spring compressed so it loses tension and the wrench reads inaccurately. The tool should be wound back to its lowest setting before storage.

Question 25Use of hand tools, measuring instruments, and test equipment

When measuring a cylinder bore with a bore gauge, the instrument should be rocked slightly in the bore to find the true diameter. What does this rocking motion accomplish?

  1. It checks the bore for taper only
  2. It locates the smallest reading, which is the true diameter Correct answer.
  3. It warms the gauge for accuracy
  4. It removes carbon from the bore wall

Explanation

A bore gauge is set to a known size and then rocked in the bore; the smallest reading occurs when the gauge is square to the bore axis and represents the true diameter. Any larger reading means the gauge is tilted.

Question 26Use of hand tools, measuring instruments, and test equipment

What is the primary purpose of a feeler gauge in engine service?

  1. Measuring the thickness of a brake disc
  2. Measuring torque on a cylinder head bolt
  3. Checking clearances such as valve lash or spark plug gap Correct answer.
  4. Testing battery electrolyte density

Explanation

A feeler gauge is a set of blades of known thickness used to check a gap or clearance, such as valve lash or a spark plug gap. The blade that fits with slight drag indicates the clearance.

Question 27Use of hand tools, measuring instruments, and test equipment

A digital multimeter is set to the 20 V DC range and connected across a battery. The display shows 12.4 V. What does this reading indicate?

  1. The battery is at roughly half charge and needs attention Correct answer.
  2. The meter is on the wrong range
  3. The battery has an open circuit
  4. The battery is fully charged at 100 percent state of charge

Explanation

A healthy fully charged 12 V lead-acid battery rests near 12.6 V, so 12.4 V indicates a partial state of charge of roughly half. The reading is valid because it falls within the selected 20 V DC range.

Question 28Use of hand tools, measuring instruments, and test equipment

Which test instrument is used to check whether an alternator diode is faulty by measuring ripple?

  1. A digital multimeter set to AC volts Correct answer.
  2. A compression tester
  3. A hydrometer
  4. A timing light

Explanation

A faulty alternator diode produces excessive AC ripple on the charging output, which is detected by measuring AC voltage across the battery with the engine running. A good charging system shows only a small AC ripple.

Question 29Use of hand tools, measuring instruments, and test equipment

A technician uses a compression tester and gets a low reading on one cylinder. Adding a few drops of oil raises the reading significantly. What does this result suggest?

  1. A burnt exhaust valve
  2. A stuck intake valve
  3. A worn piston ring or cylinder wall Correct answer.
  4. A leaking head gasket

Explanation

Oil temporarily seals the gap between a worn piston ring and cylinder wall, so a reading that rises after oil is added points to ring or bore wear. Valve or gasket leakage is not sealed by oil in this way.

Question 30Use of hand tools, measuring instruments, and test equipment

Which tool is appropriate for removing a stubborn wheel bearing nut that is torqued to 200 N·m?

  1. A 3/8 inch drive ratchet with a short extension
  2. A torque wrench used to loosen the nut
  3. A breaker bar with the correct six-point socket Correct answer.
  4. A pair of locking pliers

Explanation

A breaker bar is designed to transmit high loosening torque without damaging its mechanism, and a six-point socket grips the nut securely. A torque wrench should never be used for loosening because it can damage the calibration.

Question 31Use of hand tools, measuring instruments, and test equipment

When using a dial indicator to check flywheel runout, where should the indicator probe contact the surface?

  1. On the machined friction face near the outer edge Correct answer.
  2. On the center hub only
  3. On the starter ring gear teeth
  4. On the bolt heads holding the flywheel

Explanation

Runout is measured on the machined friction surface because that is the face that must run true against the clutch disc. The probe is set perpendicular to the surface and the flywheel is rotated to record total deflection.

Question 32Use of hand tools, measuring instruments, and test equipment

A vernier caliper main scale reads 24 mm and the vernier scale line that aligns is the 30th division on a 0.02 mm caliper. What is the measurement?

  1. 24.60 mm Correct answer.
  2. 24.03 mm
  3. 24.06 mm
  4. 24.30 mm

Explanation

On a 0.02 mm vernier caliper each vernier division represents 0.02 mm, so 30 divisions equal 0.60 mm. Adding this to the 24 mm main scale reading gives 24.60 mm.

Question 33Use of hand tools, measuring instruments, and test equipment

What is the correct way to clean a precision micrometer before measuring?

  1. Scrub the anvils with emery cloth
  2. Wipe the anvils with a clean cloth and check for burrs Correct answer.
  3. Oil the anvils heavily to reduce friction
  4. Leave coolant residue on the anvils as a lubricant

Explanation

Measuring faces must be clean and free of grit, oil film, and burrs so the anvils close squarely on the work. A soft clean cloth is used, and the zero check is repeated after cleaning.

Question 34Use of hand tools, measuring instruments, and test equipment

A technician must measure the depth of a blind hole in a cylinder head to 0.05 mm accuracy. Which instrument is best suited?

  1. An outside micrometer
  2. A feeler gauge
  3. A depth micrometer or the depth rod of a vernier caliper Correct answer.
  4. A steel rule

Explanation

Depth is measured with a depth micrometer or the depth rod of a vernier caliper, both of which reference the surface around the hole and read the distance to the bottom. A steel rule is too coarse for 0.05 mm.

Question 35Use of hand tools, measuring instruments, and test equipment

Which safety practice applies when using a pneumatic impact wrench to remove lug nuts?

  1. Wear eye protection and keep the socket fully seated on the nut Correct answer.
  2. Disconnect the air line while the tool is running
  3. Hold the socket with a gloved hand while it spins
  4. Point the tool toward yourself to watch the nut

Explanation

Impact sockets can shatter or slip, so eye protection is required and the socket must be fully seated before the trigger is pulled. Hands are kept clear of the rotating socket to avoid injury.

Question 36Use of hand tools, measuring instruments, and test equipment

A timing light with an inductive pickup is clamped over the number one cylinder's spark plug wire. What does the flashing indicate?

  1. The coolant temperature
  2. The fuel injector pulse width
  3. The alternator output frequency
  4. The moment the number one cylinder fires Correct answer.

Explanation

The inductive pickup senses the current pulse in the spark plug wire and flashes the light at the instant that cylinder fires. Aiming the flash at the timing marks then shows ignition timing relative to the crankshaft.

Question 37Use of hand tools, measuring instruments, and test equipment

When a torque wrench is used to tighten a fastener, what does the click or break-over signal indicate?

  1. The fastener has reached the set torque Correct answer.
  2. The thread has stripped
  3. The wrench needs lubrication
  4. The socket is the wrong size

Explanation

A click-type torque wrench releases or clicks when the preset torque is reached, telling the technician to stop applying force. Tightening beyond the click over-torques the fastener.

Question 38Use of hand tools, measuring instruments, and test equipment

A technician is checking valve clearance and finds the specified clearance is 0.25 mm. A 0.25 mm blade fits with slight drag and a 0.30 mm blade will not enter. What conclusion is correct?

  1. The clearance is too loose and must be adjusted
  2. The clearance is within specification Correct answer.
  3. The clearance is too tight and must be adjusted
  4. The feeler gauge set is defective

Explanation

The specified blade fitting with slight drag while the next larger blade is refused shows the clearance matches the specification. No adjustment is needed for that valve.

Question 39Use of hand tools, measuring instruments, and test equipment

Why should a digital multimeter be set to the highest range before measuring an unknown voltage, then stepped down?

  1. To increase the internal resistance of the circuit
  2. To discharge the circuit
  3. To avoid polarity errors
  4. To protect the meter from over-range damage and get an accurate reading Correct answer.

Explanation

Starting on the highest range prevents an over-range condition that can damage the meter, and the technician then steps down to the range that gives the best resolution. This is standard practice for unknown voltages.

Question 40Use of hand tools, measuring instruments, and test equipment

A technician uses a vacuum gauge connected to the intake manifold of a healthy engine at idle. What reading is expected at sea level?

  1. A rapidly fluctuating needle between 0 and 200 mm Hg
  2. Full atmospheric pressure
  3. About 430 to 560 mm Hg of steady vacuum Correct answer.
  4. Zero

Explanation

A healthy engine at idle produces a steady manifold vacuum of roughly 430 to 560 mm Hg at sea level, and the needle should be steady. A low or fluctuating reading points to a leak, restriction, or mechanical fault.

Question 41Use of hand tools, measuring instruments, and test equipment

Which instrument is used to measure the specific gravity of battery electrolyte?

  1. A manometer
  2. A pyrometer
  3. A refractometer only
  4. A hydrometer Correct answer.

Explanation

A hydrometer draws electrolyte into a tube and floats a weighted bulb to show specific gravity, which indicates state of charge. A refractometer can also be used, but a hydrometer is the classic dedicated instrument.

Question 42Use of hand tools, measuring instruments, and test equipment

A technician uses a straightedge and feeler gauge to check a cylinder head for warpage. The straightedge is placed diagonally and along the length of the head. Why are multiple directions checked?

  1. To detect warpage that may run in any direction across the surface Correct answer.
  2. To confirm the head bolt torque
  3. To measure valve seat depth
  4. To find the highest point for machining

Explanation

Warpage can occur along the length, across the width, or diagonally, so the straightedge is placed in several directions and the gap under it is measured with a feeler gauge. The largest gap found determines whether the head is within the flatness limit.

Question 43Use of hand tools, measuring instruments, and test equipment

A micrometer reading shows 5.5 mm on the sleeve and the thimble line at 28 on a 0.01 mm micrometer. What is the measurement?

  1. 5.50 mm
  2. 5.58 mm
  3. 5.28 mm
  4. 5.78 mm Correct answer.

Explanation

On a 0.01 mm micrometer the thimble has 50 divisions per revolution, so each division is 0.01 mm. The thimble reading of 28 divisions equals 0.28 mm, which is added to the 5.50 mm sleeve reading to give 5.78 mm.

Question 44Use of hand tools, measuring instruments, and test equipment

What is the correct procedure for using a file to smooth a metal bracket in the shop?

  1. Apply heavy pressure on the return stroke only
  2. Drag the file backward across the work at high speed
  3. Use steady forward pressure and lift the file on the return stroke Correct answer.
  4. Use the file without a handle for better control

Explanation

A file cuts on the forward stroke, so steady pressure is applied then and the file is lifted slightly on the return to avoid dulling the teeth. A secure handle is required for safety and control.

Question 45Engine mechanical and cooling system servicing

When removing a cylinder head from an engine, in what order should the head bolts normally be loosened?

  1. In the reverse of the specified tightening sequence, working from the outside toward the center Correct answer.
  2. All at once after heating the head to operating temperature
  3. From front to back in a straight line regardless of pattern
  4. In the specified tightening sequence, working from the center outward

Explanation

Cylinder head bolts are loosened gradually in the reverse of the tightening sequence, moving from the outer bolts toward the center. This releases clamping load evenly and reduces the risk of warping a head that may still be hot or stressed. Tightening is always done center-out in stages, but loosening is the opposite.

Question 46Engine mechanical and cooling system servicing

A coolant thermostat that stays stuck open will most likely cause which condition?

  1. The radiator cap to release coolant continuously
  2. The engine to overheat rapidly at idle
  3. The engine to warm up slowly and run below normal operating temperature Correct answer.
  4. The water pump to cavitate at high speed

Explanation

A thermostat stuck open allows continuous full coolant flow through the radiator, so the engine warms up slowly and may run below its designed temperature. This raises fuel consumption and heater performance suffers, but it does not usually cause overheating. Overheating is the classic symptom of a thermostat stuck closed.

Question 47Engine mechanical and cooling system servicing

Which component drives the water pump on a typical engine using a single serpentine belt?

  1. The starter motor through a reduction gear
  2. The cooling fan motor through an electrical coupling
  3. The camshaft directly by gear mesh in all designs
  4. The crankshaft pulley via the accessory drive belt Correct answer.

Explanation

On a serpentine-belt engine the water pump pulley is driven by the accessory drive belt from the crankshaft pulley. Belt tension and pulley alignment are therefore critical to coolant circulation. Some engines use a timing-belt-driven pump, but that is a design-specific exception rather than the general case.

Question 48Engine mechanical and cooling system servicing

What is the primary purpose of pressure-testing a cooling system?

  1. To measure the specific gravity of the coolant
  2. To verify the thermostat opening temperature
  3. To locate leaks while the engine is cold and not running Correct answer.
  4. To check the water pump impeller clearance

Explanation

A pressure tester applies air pressure to a cold, non-running system so leaks can be found by watching for pressure drop or visible seepage. Testing cold avoids scalding and false readings from expansion. It does not measure coolant concentration, thermostat opening, or internal pump clearance.

Question 49Engine mechanical and cooling system servicing

During valve clearance adjustment on an overhead-valve engine with adjustable rockers, the feeler gauge should slide with what resistance?

  1. Heavy resistance requiring the gauge to be forced
  2. No resistance at all so the gauge falls through
  3. Only the go/no-go gauge must fit, and the no-go must also fit
  4. A light, slight drag that confirms contact without force Correct answer.

Explanation

The correct clearance is reached when the feeler gauge passes with a slight, even drag, indicating contact but not binding. Too loose gives noisy valvetrain and lost lift; too tight risks burnt valves and compression loss. The no-go gauge should not fit if the clearance is correct.

Question 50Engine mechanical and cooling system servicing

Which coolant type is typically specified for engines with aluminum radiators and modern OAT corrosion inhibitor packages?

  1. Methanol-based antifreeze
  2. Plain tap water with no additives
  3. Used engine oil mixed with water
  4. Extended-life organic acid technology coolant in the color specified by the manufacturer Correct answer.

Explanation

Modern aluminum cooling systems normally specify extended-life OAT or hybrid coolant matched to the manufacturer's specification. The inhibitor package protects aluminum, solder, and gasket materials from corrosion and cavitation. Plain water, methanol, or oil will not provide the required freeze, boil, and corrosion protection.