C licence questions
CMechanics and maintenance·156 questions
Mechanics and maintenance questions — C licence
156 exam-style Mechanics and maintenance questions for the C licence with correct answer and explanation. Practice free, no signup.
- A lorry has an expansion tank marked MIN and MAX. When checking coolant with a cold engine according to the manufacturer’s instructions, must you inspect the level?
- In a combustion engine with a turbocharger and intercooler, where is the intake air filter located?
- On a road surface in good condition, the steering wheel vibrates particularly at certain speeds. Which of these mechanical causes may produce this?
- On ice, up to what multiple of the normal braking distance on a dry road may a vehicle need?
- A lorry travels at night, between sunset and sunrise, on an insufficiently lit road through a built-up area. Which lights must it use?
- What does adjusting the headlights of your lorry's lighting system involve?
- Which statement about braking distance on an icy road compared with a dry road at the same speed is correct?
- To check a lorry’s oil level with the dipstick, its manufacturer specifies checking before starting, with a cold engine and the vehicle on level ground. What should you do?
- In a flooded lead-acid battery with vented caps, what are the vent openings for?
- If you keep your vehicle's tyres at the correct pressure, you will ensure that...
- In a lorry with pneumatic brakes equipped with an air dryer, which device removes moisture from compressed air to reduce the risk of freezing?
- If you anticipate needing to slow down, which behaviour supports efficient driving without compromising safety?
- When the tyre inflation pressure of your truck is higher than recommended...
- What is the purpose of a heat exchanger mechanism or intercooler?
- If the driver of a lorry observes that a vehicle has indicated its intention to turn left, may they overtake it on the right?
- One of the factors that affects driving safety is...
- If, when operating the direction indicator, the warning lamp flashes faster than normal, this indicates that...
- If a warning appears in a C1 or C truck indicating a major fault, the correct action is to:
- A lorry will overtake a cyclist outside a built-up area on a road with one lane in each direction. What minimum lateral separation must it maintain, in addition to the other overtaking requirements?
- When overtaking a car with a lorry, what safe lateral separation must be left?
- What type of oil is a lubricant classified SAE 15W-40?
- A lorry has hydraulic power steering with a reservoir marked MIN and MAX. Should its fluid level be checked?
- In a lorry diesel engine, what may abnormal black exhaust smoke be associated with?
- A lorry has a battery master switch. If the instrument panel receives no power when the ignition is switched on, what initial check concerning that switch should be made?
- In a lorry with a synchronised manual gearbox, does unnecessary double-declutching with extra throttle blips and slower shifts support efficient driving?
- In a diesel engine with a conventional turbocharger lubricated by the engine oil circuit, what oil lubricates its bearings?
- A steering fault in a C1 or C truck:
- How is the normal operating temperature of an engine’s coolant determined?
- If a road vehicle’s tyres, when cold, have less pressure than specified by the manufacturer for its load and use...
- In efficient driving with a manual synchronised gearbox in good condition, why avoid unnecessary double-declutching?
- What is a lubricating oil with SAE 15W-40 specification?
- If, due to traffic requirements, a truck with a maximum authorised mass (MAM) of more than 3,500 kg becomes immobilised inside an underpass, among other obligations, the driver must...
- You park a 4,000 kg MAM lorry on a significant uphill gradient and leave the seat. In addition to stopping the engine, disconnecting the starting system, applying the parking brake and selecting first gear or P, which option is valid if there is a kerb?
- What is the function of the oil filter?
- When checking a lorry’s engine oil level with the dipstick under manufacturer instructions, on what ground should it be parked?
- At the same speed, which driver-related factor can increase the distance travelled from perceiving danger until braking begins?
- While driving your lorry, you notice that it veers towards one side of the carriageway only when you press the brake pedal. What could this be due to?
- What are the crankshaft surfaces that rotate in the engine block’s main bearings called?
- A liquid-cooled lorry has an expansion tank marked MIN and MAX. When checked under manufacturer instructions, how should the level be?
- To compare and adjust lorry tyre pressure to the recommended cold value for its load, when should it be checked?
- In a worm-gear steering system, how does the steering wheel return to its rest position (straight-ahead line)?
- Other conditions being equal, how may tyre pressure below the recommendation for the load affect fuel consumption?
- A lorry has an operational electric retarder and descends a steep gradient with suitable grip. Under manufacturer instructions, how should it be combined with the service brake?
- A breakdown leaves a lorry immobilised on the carriageway or shoulder of an insufficiently lit through-road within a built-up area, between sunset and sunrise. Which lights must remain on?
- On a vehicle with a hydraulically actuated clutch, where should fluid level be checked following manufacturer instructions?
- With a small tread puncture where the object remains embedded, which tyre usually loses air more slowly than a tyre with an inner tube?
- In a combustion-engine vehicle with electronic injection that does not require accelerator input to start, which practice avoids unnecessary fuel use when starting the engine?
- What is the “fading” effect that a vehicle's brakes can suffer from?
- In a combustion engine with a turbocharger and intercooler, where is the intake air filter located?
- Before driving a truck, which option includes checks of its safety systems rather than only fuel or cleanliness?
- A lorry driver sees the vehicle ahead clearly indicating its intention to turn left. If no other rule or sign prohibits it, may the lorry overtake on the right?
- Two batteries, each with a nominal voltage of 12 V, are correctly connected in series so that their voltages add. What is the combination’s nominal voltage?
- An insulated vehicle has a mechanical-compression or absorption refrigeration unit that lowers and maintains its body temperature. Which specific vehicle classification applies?
- Should you periodically check the level of the windscreen washer fluid?
- If a vehicle's steering system shows unstable behaviour and pulls to one side, what should we check?
- In an internal-combustion engine, what does persistent bluish-white exhaust smoke associated with high oil consumption usually indicate?
- If the lorry I am driving has a hydraulically operated braking circuit, I must...
- When the shock absorber deteriorates and loses effectiveness over time, how does this affect the suspension?
- What does the word “TUBELESS” written on the side of the tyre indicate?
- If an exhaust silencer is broken and no longer properly attenuates engine noise, what effect does this have?
- What properties should a gearbox gear lubricant have?
- In a conventional four-cylinder, four-stroke engine, how far does the crankshaft rotate during one complete piston stroke from one dead centre to the other?
- By definition, a heated lorry is a motor vehicle that is:
- While driving your lorry, you notice that it veers towards one side of the carriageway only when you press the brake pedal. What could this be due to?
- As a general rule, stopping on urban roads shall be carried out by positioning the vehicle…
- In an electrical diagram with two identical compatible 12 V nominal batteries suitable for series connection, which link gives 24 V nominal between the two free terminals?
- What should I do to drive efficiently?
- If you are driving your lorry downhill, can you put it in neutral to save fuel?
- At the same speed and with the same lorry, a wet road reduces grip compared with a dry road. If you do not intend to overtake, how should you adjust your gap from the vehicle ahead?
- Fog significantly reduces visibility. In addition to the compulsory position lights, may you use dipped headlights without switching on the front fog lights?
- One of the components that forms part of the pneumatic braking system is...
- At the same speed and with the same vehicle, a wet road reduces grip compared with a dry road. What happens to braking distance?
- Among the different systems that make up a vehicle's engine, which one does the catalytic converter belong to?
- Under comparable driving conditions, which tyre condition tends to increase fuel consumption?
- Passive safety systems are...
- If you notice a major fault in the brakes or steering of a C1 or C truck, the correct action is to:
- In the tyre marking 385/65 R22.5, what does the number 22.5 indicate?
- What maintenance should we carry out on the cooling system?
- What benefit is supported by keeping lorry tyres at the recommended cold pressure for their load?
- Which of the following parameters affects the adjustment of the driver's seat?
- In a C1 or C truck, correct tire pressure:
- Under comparable conditions and as a general rule, tyre grip is usually lower when driving on…
- In a conventional system whose coolant pump is belt-driven from the engine, which component supplies movement to that belt?
- The driver of a lorry with a MAM exceeding 3,500 kg must leave the driving position when parking on a steep upward slope with a kerb. If securing it by resting a steered wheel against the kerb instead of using chocks, which way should the wheels face?
- Light rain does not significantly reduce visibility. There is no fog, smoke, dust or other visibility-reducing condition, and you are not on a narrow road section with many signposted bends. May you switch on fog lights solely because of that rain?
- In a cooling circuit designed to operate under pressure, what effect does increased pressure have on the boiling temperature of the same coolant?
- After passing through a puddle, your lorry’s brakes may be wet. When it is safe to check, which operation should you verify especially?
- If you notice unusual noises or vibrations in a C1 or C truck, the prudent action is to:
- Between sunset and sunrise, you drive a lorry on a sufficiently lit road through a built-up area. Besides position lights, which headlights must you use?
- With the same oil and engine speed, other factors being equal, which oil condition can favour lower pressure by reducing its viscosity?
- If a warm engine persistently emits bluish exhaust smoke, what may this indicate?
- Will I need to carry out any special maintenance if my vehicle's engine uses a timing belt drive system?
- A combination of vehicles consisting of a motor vehicle coupled to a semi-trailer is known as:
- The manufacturer specifies a 12 V system using two compatible 12 V batteries connected in parallel. How are their terminals linked in that connection?
- In a lorry’s friction clutch with a manual gearbox, which component is pressed against the flywheel to transmit engine rotation to the gearbox input?
- On a long descent, what can you do to stop the vehicle from gradually gaining speed?
- In a conventional manual gearbox and bevel-gear differential, what lubricant is normally used for the gears, respecting each unit’s specification?
- On a road surface in good condition, the steering wheel vibrates particularly at certain speeds. Which of these mechanical causes may produce this?
- Can a manufacturer-specified and integrated electromagnetic retarder operate in a vehicle equipped with ABS?
- A heat-exchanging mechanism, or intercooler, achieves...
- An articulated vehicle is defined as…
- What does the pressure gauge in the lubrication system indicate?
- An insulated vehicle has a mechanical-compression or absorption refrigeration unit that lowers and maintains its body temperature. Which specific vehicle classification applies?
- What does the word 'tubeless' mean on a tyre?
- When the windscreen washer reservoir is low, how should you replenish it?
- For efficient driving of a vehicle with a working synchromesh manual gearbox whose manufacturer does not require double-clutching, how should you normally change gear?
- When driving a vehicle with a manual gearbox and clutch pedal, what helps avoid unnecessary transmission wear?
- When you turn on the ignition, the oil warning light comes on, and it goes off once the engine starts. What is this due to?
- At the same engine speed with no other changes, if oil becomes hotter and its viscosity decreases, how can this affect lubrication pressure?
- If your vehicle is fitted with a petrol engine and has a catalytic converter in the exhaust, what fuel should you use?
- Stopping distance is divided into...
- What does the aiming (adjustment) of a lorry's headlights consist of?
- When leaving the driving position after parking a 6,000 kg MAM lorry with a manual gearbox on a noticeable 8% slope, besides stopping the engine and taking applicable precautions, what must you do?
- In a truck, preventive maintenance of the braking system is important because:
- When driving on a stretch of road that is flooded with water, what consequences can a shock absorber in poor condition have?
- A driver without specialist training should leave replacement of certain lamps to a workshop because of high-voltage risk. Which lamps does this precaution concern?
- In a serviceable flooded lead-acid battery, the level has fallen through normal water loss during use. Following manufacturer instructions, what should be added to restore it?
- The engine oil dipstick is used to check...
- What is the part of the tyre that rests on the ground called?
- On a lorry with hydraulic power steering and a reservoir marked MIN and MAX, should you check its fluid level?
- In a hydraulic braking system, the pedal feels spongy and temporarily improves after repeated applications. Which of these may be a cause in the hydraulic circuit?
- When parking a vehicle with a trailer on a noticeable uphill gradient and leaving the driving position, a suitable kerb is available but no wheel chocks. In addition to the other immobilisation measures, what should you do?
- In an engine, besides lubricating the moving parts and the cylinder walls, what other purpose does the oil serve?
- In a liquid-cooled engine whose coolant pump is belt-driven, which fault may reduce coolant circulation and cause overheating?
- A heavy lorry has a working electric retarder. On a steep descent with adequate grip and use permitted by the manufacturer, how should it be used to reduce sustained demand on the service brakes?
- In a vehicle with a manual gearbox and a working conventional pedal clutch, when is the clutch engaged, coupling the engine to the gearbox input?
- Before driving a lorry through very cold areas, what should you check about its coolant?
- A lorry has a body with insulated walls, doors, floor and roof to limit heat transfer, without a cold source or refrigeration equipment. Which type does this describe?
- Should I regularly check the windscreen washer fluid level?
- Which gas is produced by complete combustion of the carbon in petrol or diesel fuel?
- Under the conventional arrangement described in the DGT mechanics manual, where is the engine cooling-system thermostat generally located?
- What main function do road-tyre tread grooves serve on a wet road?
- A lorry circuit requires nominal 24 V and has two compatible 12 V batteries. Which connection adds their voltages?
- An electrical accessory does not work while the others operate normally. The manual says to check its overcurrent protection first. Which component should you check?
- In a diesel engine with a conventional mechanical injection pump and rack-controlled fuel delivery, which assembly includes the governor that limits maximum engine speed?
- In a conventional four-cylinder, four-stroke engine, how far does the crankshaft rotate during one complete piston stroke from one dead centre to the other?
- If, due to traffic conditions, a lorry with an MAM (maximum authorised mass) of more than 3,500 kg becomes stationary inside an underpass, among other obligations, the driver must...
- For an N2 or N3 lorry subject to Royal Decree 1417/2005, what speed must its compulsory limiter prevent it from exceeding?
- Is an articulated vehicle a vehicle combination?
- An insulated lorry uses a cold source other than mechanical compression or absorption equipment to lower and maintain its internal temperature. What specific cooling classification applies?
- A lorry is driven at night, with good visibility and no conditions permitting fog-light use. May it travel with position lights alone?
- In a lorry with a liquid-cooled combustion engine, the engine takes abnormally long to reach operating temperature. Which component regulates coolant flow to the radiator and should be checked?
- What risk does brake overheating from excessive use, for example on a long descent, create?
- When checking engine oil level with a dipstick, what conditions should you follow?
- In a conventional liquid-cooling circuit with a thermostat and internal bypass, how does the thermostat help a cold engine warm up?
- What does the word TUBELESS printed on the side of the tyre mean?
- During normal driving while maintaining steering control, the vehicle persistently pulls to one side without an apparent road or wind cause. What should you do?
- By day, a lorry without front fog lamps and with no main beam in use travels on an interurban road in light snowfall that significantly reduces visibility, without particularly adverse conditions. Which lights must it use?
- Between sunset and sunrise, a lorry travels on a sufficiently lit through-road in a built-up area with no adverse weather. In addition to position lights, which lights must it use?
- When leaving the driving position after parking a 6,000 kg MAM lorry with a manual gearbox on a noticeable 8% slope, besides stopping the engine and taking applicable precautions, what must you do?
- What general term covers changes such as joining traffic, moving into another lane or turning, which alter the vehicle’s normal progress?
- Before starting the day with a truck it is advisable to carry out:
- If my lorry's steering is hydraulically assisted, should I check the steering fluid level?
- What benefit is supported by keeping lorry tyres at the recommended cold pressure for their load?
- If your lorry’s engine takes too long to reach normal operating temperature, which component should be checked?
- Your lorry has a coolant expansion tank marked MIN and MAX. Under the manufacturer’s specified checking conditions, how should you check its level?
How to ace the mechanics and maintenance questions on the C licence
Mechanics and maintenance questions are usually among the highest-failure areas in the C licence exam. Each of the 156 exam-style questions here includes the options, the correct answer and an explanation of why it's correct.
The most effective way to master this topic is to alternate syllabus reading with question practice. Start by reading the full topic, then click into any question to study it in detail. Failed questions enter the smart-review queue until you master them.
Frequently asked questions about mechanics and maintenance on the C licence
- How many mechanics and maintenance questions are in the C licence question bank?
- Our exam-style question bank includes 156 mechanics and maintenance questions for the C licence. Each comes with the correct answer and explanation.
- How should I study mechanics and maintenance for the C licence exam?
- The C test has 20 questions. Use this bank to practise mechanics and maintenance with explanations, and combine topic review with full mock exams.
- What are the most common mechanics and maintenance mistakes?
- Three typical causes: 1) misreading prompts with decisive keywords ("always", "never", "except", "only", "at least") — they flip the correct answer; 2) switching correct answers in the final review due to self-induced doubt; 3) studying only by topic without full simulations, which penalises block-switching speed.
- How should I practise mechanics and maintenance to prepare for the C licence?
- Alternate three modes: first study the full topic syllabus; then practise the 156 exam-style mechanics and maintenance questions until you understand the logic of each; finally launch full C-licence simulations (20 questions, max 2 wrong) to train block-switching under pressure.