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Red Seal Automotive practice questions

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Question 1Common Occupational Skills

While grinding metal on a bench grinder, the minimum eye protection a technician must wear is:

  1. Safety glasses with side shields Correct answer.
  2. A face shield worn alone
  3. Tinted goggles for glare
  4. A welding helmet

Explanation

Impact-rated safety glasses with side shields are the minimum protection for grinding, because particles travel in all directions. A face shield is designed to be worn over safety glasses, not instead of them.

Question 2Common Occupational Skills

A vehicle has been raised with a hydraulic floor jack. Before the technician works underneath it, the vehicle must be:

  1. On the jack with the valve closed
  2. On rated jack stands at the lift points Correct answer.
  3. Blocked at the wheels only
  4. Held by the hoist arms

Explanation

A floor jack is a lifting device only; its seal can bleed down and let the vehicle fall. Rated jack stands placed at the manufacturer's support points carry the load safely while work is performed.

Question 3Common Occupational Skills

Which class of fire extinguisher is intended for flammable liquid fires such as gasoline?

  1. Class A
  2. Class C
  3. Class B Correct answer.
  4. Class D

Explanation

Classes are assigned by the fuel involved: Class B covers flammable and combustible liquids such as gasoline, solvents and oils. Using the wrong class can spread the fire or fail to smother it.

Question 4Common Occupational Skills

A shop chemical container carries the WHMIS pictogram showing a skull and crossbones. This pictogram means the product:

  1. Can cause serious toxicity or death Correct answer.
  2. Is a compressed gas
  3. Is an oxidizing hazard
  4. Causes corrosion to skin and metal

Explanation

The skull and crossbones is the WHMIS acute toxicity symbol, used for products that can cause serious illness or death from short-term exposure. It signals the need for the safety data sheet review and strict handling precautions.

Question 5Common Occupational Skills

A feeler gauge is the correct tool to measure:

  1. The gap between two mating surfaces Correct answer.
  2. The runout of a rotating part
  3. The depth of a blind bore
  4. The outside diameter of a shaft

Explanation

A feeler gauge is a set of blades of known thickness used to check clearances such as valve lash, spark plug gaps and bearing end play. The blade that fits with slight drag indicates the clearance.

Question 6Common Occupational Skills

Which socket is correct for use on an impact wrench?

  1. A black impact-rated socket Correct answer.
  2. A 12-point chrome socket
  3. A socket with a cracked wall
  4. A chrome-plated hand socket

Explanation

Impact sockets are made from a tougher, less brittle steel and are marked as impact rated, so they resist the shock loading of an impact wrench. Chrome hand sockets can crack or shatter under that load.

Question 7Common Occupational Skills

In the metric (SI) system, torque is correctly expressed in:

  1. Kilograms (kg)
  2. Newtons (N)
  3. Newton metres (N·m) Correct answer.
  4. Kilopascals (kPa)

Explanation

Torque is a force acting at a distance from an axis, so its unit is the newton multiplied by the metre. Pressure uses pascals, force uses newtons and mass uses kilograms.

Question 8Common Occupational Skills

A metric micrometer with 0.01 mm thimble graduations shows the sleeve at the 7.5 mm mark and the thimble at the 28th line. What is the measurement?

  1. 7.58 mm
  2. 7.78 mm Correct answer.
  3. 7.28 mm
  4. 7.50 mm

Explanation

The sleeve contributes 7.50 mm, including the half-millimetre mark that is visible. The thimble adds 28 × 0.01 mm = 0.28 mm, giving a total of 7.78 mm.

Question 9Common Occupational Skills

Cylinder head bolts that are tightened to a torque plus a specified turning angle should be:

  1. Reused if they thread in freely by hand
  2. Reused after coating them with thread locker
  3. Reused after cleaning the threads
  4. Replaced with new bolts Correct answer.

Explanation

Torque-to-yield bolts are tightened past their elastic limit so they stretch permanently and hold clamp load through spring tension. Once stretched they cannot be reused, because a second stretch leaves insufficient clamping force.

Question 10Common Occupational Skills

Before raising a vehicle on a two-post hoist, the technician should:

  1. Place the lift pads at the recommended lift points Correct answer.
  2. Stand underneath to guide the arms
  3. Leave the doors open to watch clearance
  4. Raise it fully, then check the pads

Explanation

Lift pads must be spotted at the manufacturer's designated lift points before the vehicle leaves the floor, so the load is carried by structural areas. A stability check is then made at low height before full raising.

Question 11Common Occupational Skills

Used engine coolant drained during a repair should be:

  1. Poured onto gravel behind the shop
  2. Poured into the sanitary sewer with water
  3. Mixed with used engine oil for disposal
  4. Collected in a labelled container for recycling Correct answer.

Explanation

Coolant contains ethylene glycol or propylene glycol, which is toxic to humans and animals and is regulated as a waste product in most jurisdictions. It is drained into a dedicated labelled container and sent for recycling or proper disposal.

Question 12Common Occupational Skills

A dial indicator mounted on a magnetic base is best suited to measure:

  1. Valve clearance
  2. Outside diameter of a valve stem
  3. Lateral runout of a brake rotor Correct answer.
  4. Brake pad thickness

Explanation

A dial indicator converts small linear movement of a contact point into a needle reading, which makes it ideal for measuring runout, end play and backlash. The part is rotated or moved while the total needle sweep is observed.

Question 13Common Occupational Skills

The marking 8.8 on the head of a metric bolt identifies:

  1. The overall bolt length in centimetres
  2. The property class, which relates to strength Correct answer.
  3. An SAE grade 8 coarse-thread designation
  4. The nominal thread diameter in millimetres

Explanation

Metric bolts carry a two-part property class: the first number is one hundredth of the minimum tensile strength in MPa, and the second is the ratio of yield strength to tensile strength. Class 8.8 therefore indicates roughly 800 MPa tensile strength.

Question 14Common Occupational Skills

For a metric thread, the tap drill is selected so the drilled hole is approximately:

  1. Equal to the pitch diameter
  2. Half the major diameter
  3. Major diameter minus the thread pitch Correct answer.
  4. Major diameter plus the thread pitch

Explanation

Subtracting the pitch from the major diameter gives a hole close to the thread's minor diameter, leaving about 75 percent thread engagement for the tap to cut. This is the standard quick calculation used to pick a tap drill.

Question 15Common Occupational Skills

After completing a repair, the technician's work order should record:

  1. Only the total labour time charged
  2. Only the price of the parts installed
  3. The customer's complaint, copied word for word
  4. The cause, correction and parts used Correct answer.

Explanation

A complete repair record shows what was found, what was done and which parts were installed, so the repair can be verified, warranted and repeated if needed. It also protects both the shop and the customer if a dispute arises.

Question 16Common Occupational Skills

Before electric arc welding on a vehicle, the technician should:

  1. Disconnect the battery and ground close to the weld Correct answer.
  2. Leave the battery connected so voltage stays stable
  3. Clamp the welder ground to the steel shop bench
  4. Disconnect only the engine control module harness

Explanation

Welding current follows the path of least resistance back to the welder ground, so the clamp must be close to the work to keep current out of wiring, bearings and modules. Disconnecting the battery isolates the electrical system from voltage spikes.

Question 17Common Occupational Skills

When installing a new lip seal in a hub, the technician should:

  1. Install it dry to keep it from slipping
  2. Lubricate the lip and drive it in squarely Correct answer.
  3. Coat the lip with sealant to stop leaks
  4. Drive it in until it bottoms on the bearing

Explanation

The sealing lip needs a film of the correct lubricant so it does not burn or tear during the first rotation, and the seal must enter squarely to the specified depth. A cocked or over-driven seal leaks and can block the drain-back path.

Question 18Common Occupational Skills

A telescoping gauge is used together with an outside micrometer to measure:

  1. The depth of a blind hole
  2. The inside diameter of a bore Correct answer.
  3. The runout of a shaft
  4. The pitch of a thread

Explanation

The telescoping gauge is set across the bore and locked, then measured with an outside micrometer to transfer the inside dimension. This technique allows accurate bore and cylinder measurements in the field.

Question 19Common Occupational Skills

An SAE grade 5 bolt is identified on its head by:

  1. Four radial lines
  2. Two radial lines
  3. Six radial lines
  4. Three radial lines Correct answer.

Explanation

SAE bolt grades are marked with radial lines: grade 5 uses three lines, grade 8 uses six, and unmarked bolts are grade 2. The markings let a technician match replacement fasteners to the original strength grade.

Question 20Common Occupational Skills

A crows foot adapter is fitted to a torque wrench at 90 degrees to the handle. The torque delivered to the fastener is:

  1. The same as the wrench setting Correct answer.
  2. Greater than the wrench setting
  3. Less than the wrench setting
  4. Found by multiplying the setting by a length ratio

Explanation

At 90 degrees the adapter adds almost nothing to the effective lever length, so no correction factor is applied. A correction is needed only when the adapter extends in line with the handle and changes the lever arm.

Question 21Common Occupational Skills

A pinhole leak is suspected in a pressurized hydraulic hose. The correct approach is to:

  1. Run a gloved hand along the hose to feel the leak
  2. Wipe the hose with a rag while the engine runs
  3. Tighten the fitting while the system is pressurized
  4. Relieve the pressure, then probe with cardboard Correct answer.

Explanation

Pressurized hydraulic fluid can jet through skin at a pinhole leak and cause severe injection injury, so pressure must be released before the hose is inspected. Cardboard shows the leak location without putting any body part in the fluid stream.

Question 22Common Occupational Skills

A fastener requires 100 N·m. The torque wrench measures 400 mm from the drive to the handle, and a 50 mm crows foot is fitted in line, extending the length. What should the wrench be set to?

  1. 88.9 N·m Correct answer.
  2. 78.4 N·m
  3. 100.0 N·m
  4. 112.5 N·m

Explanation

The adapter lengthens the lever arm, so the wrench must be set below the specified torque using setting = torque × wrench length ÷ total length. That gives 100 × 400 ÷ 450 = 88.9 N·m.

Question 23Common Occupational Skills

A metric vernier caliper divides 49 main-scale millimetres into 50 vernier divisions. The least count of the tool is:

  1. 0.05 mm
  2. 0.10 mm
  3. 0.01 mm
  4. 0.02 mm Correct answer.

Explanation

The main scale advances 1 mm per division while the vernier advances 0.98 mm, so each vernier division represents a difference of 0.02 mm. That value is the smallest increment the caliper can resolve.

Question 24Common Occupational Skills

Which practice damages a click-type torque wrench?

  1. Using it to break loose a seized fastener Correct answer.
  2. Pulling smoothly until the wrench clicks
  3. Storing it in its case at the lowest setting
  4. Wiping the scale with a dry cloth

Explanation

A click-type wrench is a measuring instrument and is loaded only in the tightening direction to its set value. Using it to loosen a stuck fastener applies loads far above its range and knocks the calibration out.

Question 25Engine and Engine Support Systems

What is the primary function of the thermostat in an engine cooling system?

  1. To purge air from the cooling system during warm-up
  2. To raise the coolant boiling point by pressurizing the system
  3. To control coolant flow so normal operating temperature is maintained Correct answer.
  4. To drive the water pump impeller at the correct speed

Explanation

The thermostat is a temperature-sensitive valve that stays closed while the engine is cold so coolant bypasses the radiator, then opens progressively to regulate coolant flow and hold the engine near its designed operating temperature.

Question 26Engine and Engine Support Systems

What is the primary purpose of the engine mounts on a unitized-body vehicle?

  1. To set ignition timing relative to the transmission
  2. To keep the engine block at a constant temperature
  3. To carry crankshaft thrust loads
  4. To support the powertrain and isolate vibration Correct answer.

Explanation

Mounts carry the weight and torque reaction of the powertrain while their rubber or hydraulic elements damp vibration so it is not transmitted into the body structure.

Question 27Engine and Engine Support Systems

The component that limits maximum oil pressure in a lubrication system is the:

  1. pickup tube screen
  2. pressure relief valve in the oil pump Correct answer.
  3. oil pan windage baffle
  4. oil filter anti-drainback valve

Explanation

A spring-loaded relief valve opens when pump output pressure exceeds a set value and bypasses oil back to the pan or pump inlet, capping system pressure.

Question 28Engine and Engine Support Systems

On a late-model engine, a serpentine drive belt is kept at correct tension by:

  1. the crankshaft damper pulling the belt tight
  2. the belt's own elasticity, with no external adjustment
  3. shims placed under the alternator mounting bracket
  4. a spring-loaded automatic tensioner Correct answer.

Explanation

A spring-loaded tensioner maintains constant belt tension as the belt stretches and as accessory loads change, eliminating manual adjustment.

Question 29Engine and Engine Support Systems

A 15 psi radiator cap increases the coolant boiling point because:

  1. the cap restricts coolant flow through the radiator
  2. system pressure raises the coolant boiling point Correct answer.
  3. the cap adds coolant from the reserve tank as the engine cools
  4. the cap vents air out of the system when pressure drops

Explanation

Pressurizing a liquid raises its boiling temperature, so a cap rated at 15 psi allows the coolant to run hotter before boiling. The cap also has a vacuum valve that draws coolant back from the reserve tank as the system cools.

Question 30Engine and Engine Support Systems

Hydraulic lifters maintain zero valve lash by:

  1. centrifugal force acting on the pushrod
  2. engine oil pressure filling an internal plunger Correct answer.
  3. a spring that holds the valve off its seat
  4. using shims that are selected at assembly

Explanation

Oil pressure extends the lifter plunger until it contacts the pushrod or valve tip, taking up clearance automatically; a check valve traps oil so the lifter stays pumped up between cycles.

Question 31Engine and Engine Support Systems

On an interference engine, a broken timing belt will most likely result in:

  1. valves contacting pistons and bending Correct answer.
  2. only a check-engine light and a stored cam code
  3. the engine continuing to run with reduced power
  4. the starter failing to crank the engine

Explanation

In an interference design the piston crowns and open valves occupy the same space at different points in the cycle, so loss of cam synchronization lets pistons strike the valves.

Question 32Engine and Engine Support Systems

The positive crankcase ventilation (PCV) system:

  1. adds fresh air to the intake manifold under boost
  2. vents crankcase blow-by directly to the atmosphere
  3. prevents oil from reaching the rocker arms
  4. routes crankcase vapors into the intake to be burned Correct answer.

Explanation

Crankcase blow-by gases are drawn through the PCV valve into the intake manifold so they are burned in the engine instead of escaping to the atmosphere, and the system also keeps slight negative pressure in the crankcase.

Question 33Engine and Engine Support Systems

Coolant is seeping from the small hole under the water pump housing. This indicates:

  1. the thermostat is stuck open
  2. the radiator cap is releasing excess pressure
  3. normal operation; the hole is a drain for condensation
  4. the shaft seal has failed and the pump should be replaced Correct answer.

Explanation

The weep hole is a telltale between the shaft seal and bearing; coolant escaping there means the seal has failed and coolant is on its way to the bearing.

Question 34Engine and Engine Support Systems

A vehicle overheats intermittently and the coolant reservoir bubbles continuously while the engine runs. The most likely cause is:

  1. combustion gases leaking into the cooling system Correct answer.
  2. a faulty radiator fan clutch
  3. a thermostat that opens at too low a temperature
  4. a collapsed lower radiator hose

Explanation

Continuous bubbling in the reservoir while the engine runs is characteristic of combustion pressure entering the cooling system through a failed head gasket or cracked casting.

Question 35Engine and Engine Support Systems

Torque-to-yield cylinder head bolts are tightened to a torque value and then:

  1. reused up to three times
  2. backed off one full turn before final torque
  3. tightened only after the engine reaches operating temperature
  4. turned an additional specified angle Correct answer.

Explanation

These fasteners are designed to stretch into the yield range, so they are set by a torque-plus-angle procedure that produces a consistent clamp load regardless of friction variation.

Question 36Engine and Engine Support Systems

A hydraulic engine mount with a torn internal diaphragm will typically cause:

  1. excessive vibration and a clunk felt through the body Correct answer.
  2. coolant loss at the heater core
  3. a misfire code on one cylinder bank
  4. a low oil pressure warning at idle

Explanation

The hydraulic chamber damps motion by forcing fluid through an orifice; when the diaphragm tears, damping is lost and engine motion is transmitted to the body as vibration and noise.

Question 37Engine and Engine Support Systems

Blue exhaust smoke at startup that clears after a few seconds is most often caused by:

  1. a leaking intake manifold gasket
  2. worn valve stem seals Correct answer.
  3. worn piston rings
  4. a restricted PCV valve

Explanation

Worn stem seals let oil run down the guides into the cylinders while the engine sits; that oil burns off at startup, then the smoke stops once the oil is consumed.

Question 38Engine and Engine Support Systems

A viscous (thermal) fan clutch that has failed in the engaged position will cause:

  1. excessive fan noise at highway speed Correct answer.
  2. coolant to be pushed out of the overflow
  3. the fan to contact the radiator shroud
  4. overheating at idle only

Explanation

A clutch locked engaged drives the fan at engine speed all the time, so the fan roars and consumes power at road speed when airflow through the radiator is already adequate.

Question 39Engine and Engine Support Systems

An engine that never reaches normal operating temperature and produces weak heater output is likely to have:

  1. a thermostat stuck closed
  2. a thermostat stuck open Correct answer.
  3. a failed water pump seal
  4. a restricted heater core

Explanation

A thermostat held open lets coolant circulate through the radiator continuously, so the engine runs cold and the heater core receives lukewarm coolant.

Question 40Engine and Engine Support Systems

Which symptom best indicates a stretched timing chain on a high-mileage engine?

  1. a steady coolant temperature increase
  2. oil pressure that drops as the engine warms
  3. a hard brake pedal
  4. cam/crank correlation codes with rough running at idle Correct answer.

Explanation

As a chain wears, cam timing lags the crankshaft, so the PCM sets a correlation code and idle quality deteriorates; a rattle at startup is often heard as well.

Question 41Engine and Engine Support Systems

The torsional vibration damper (harmonic balancer) on the crankshaft is used to:

  1. carry thrust loads at the rear main bearing
  2. drive the oil pump
  3. absorb crankshaft torsional vibrations Correct answer.
  4. measure engine speed for the tachometer

Explanation

The balancer's inertia ring and elastomer layer damp the twisting vibrations that develop in the crankshaft, protecting the crank and driven accessories.

Question 42Engine and Engine Support Systems

When removing an engine with the transaxle attached from a front-wheel-drive vehicle, the safest practice is to:

  1. use a load leveler and the approved lift points Correct answer.
  2. support the engine on the oil pan while lifting
  3. attach the hoist chain to a single exhaust manifold bolt
  4. lift with the hood closed to keep the chain aligned

Explanation

A leveler lets the assembly be tilted to clear the body while load stays on factory-designed lift eyes or brackets, which are rated for the powertrain weight.

Question 43Engine and Engine Support Systems

A cylinder reads 90 psi on a dry compression test and 130 psi after oil is added. This indicates:

  1. a broken valve spring
  2. a blown head gasket
  3. worn piston rings or cylinder walls Correct answer.
  4. a burned exhaust valve

Explanation

Oil temporarily seals the ring-to-wall interface, so a significant pressure rise on the wet test points to ring or cylinder wear rather than a valve or gasket fault.

Question 44Engine and Engine Support Systems

An engine has a lean misfire at idle that improves at higher speed, and fuel trims show plus 20 percent at idle. The most likely cause is:

  1. a clogged catalytic converter
  2. a restricted air filter element
  3. a vacuum leak at the intake manifold gasket Correct answer.
  4. a restricted fuel filter

Explanation

Unmetered air entering downstream of the throttle leans the mixture most at idle, when intake vacuum is highest, so trims go positive at idle and improve as engine speed rises.

Question 45Engine and Engine Support Systems

A cooling system pressure test shows no external leaks, yet the coolant reservoir bubbles steadily while the engine runs. Which test best confirms combustion gases are entering the cooling system?

  1. A radiator cap pressure test
  2. A thermostat opening test in heated water
  3. A block tester at the radiator filler neck Correct answer.
  4. A water pump flow test with the engine running

Explanation

A block tester draws vapor from the filler neck through a chemical that changes colour in the presence of combustion gases, confirming a head gasket or casting leak.

Question 46Engine and Engine Support Systems

Excessive clearance at the main and rod bearings will have what effect on the lubrication system?

  1. lower oil pressure as oil escapes past the bearings Correct answer.
  2. higher vacuum in the crankcase
  3. no effect, since the relief valve controls pressure
  4. higher oil pressure because the pump spins faster at speed

Explanation

Oil pressure is the resistance to pump flow. Larger clearances let more oil escape, so the pump cannot build the same pressure at a given speed and the gauge or warning system responds.

Question 47Engine and Engine Support Systems

During a cylinder leak-down test, air is heard escaping from the oil filler cap. This indicates leakage past the:

  1. piston rings Correct answer.
  2. intake valves
  3. head gasket into the coolant jacket
  4. exhaust valves

Explanation

Air that reaches the crankcase escapes through the oil filler or dipstick tube, which points to ring-to-wall sealing loss or a holed piston.

Question 48Engine and Engine Support Systems

When lowering a front subframe that carries the engine on a front-wheel-drive vehicle, the engine must be:

  1. left hanging on the halfshafts
  2. removed from the vehicle first in all cases
  3. supported from above with a suitable engine support fixture Correct answer.
  4. hung from the brake lines

Explanation

A support fixture bridges the fender rails and holds the powertrain from above so the cradle can be lowered safely without overloading the halfshafts, hoses, or wiring.

Question 49Engine and Engine Support Systems

An ohmmeter reads 0.4 V between the coolant and battery ground on a vehicle with repeated heater core failures. This indicates:

  1. normal operation, since coolant is conductive
  2. stray electrical current in the cooling system Correct answer.
  3. a faulty radiator cap
  4. an air pocket in the cooling system

Explanation

A voltage reading above roughly 0.3 V suggests stray current is using the coolant as a path to ground, which corrodes aluminum and brass components such as the heater core. The usual cause is a poor body or engine ground.

Question 50Engine and Engine Support Systems

The lower torque strut (dog bone) on a transverse-mounted engine is used to:

  1. support the vertical weight of the engine and the transaxle assembly
  2. limit fore-and-aft engine rotation under acceleration Correct answer.
  3. damp crankshaft torsional vibration before it reaches the transmission
  4. reduce the transfer of road-induced vibration into the vehicle body

Explanation

A torque strut is a link between the engine and the body or cradle that resists the reaction torque of the engine, limiting how far the engine rocks fore and aft under acceleration and braking. Vertical weight is carried by the main mounts and cradle, while other jobs such as damping crank vibration or isolating road inputs belong to different components.