This subtopic covers the essential practical skills required to safely check and maintain car tyre pressures and tread depth, ensuring compliance with lega
Topic Synopsis
This subtopic covers the essential practical skills required to safely check and maintain car tyre pressures and tread depth, ensuring compliance with legal and safety standards. Learners will develop competency in using tools such as pressure gauges and tread depth indicators, and will understand the implications of incorrect tyre maintenance on vehicle performance and road safety.
Key Concepts & Core Principles
- Health and Safety: Understanding workshop safety, including fire extinguisher types, COSHH regulations, and correct use of personal protective equipment (PPE) like goggles and gloves.
- Engine Systems: Identifying major engine components (e.g., cylinder block, pistons, camshaft) and explaining the four-stroke cycle (intake, compression, power, exhaust).
- Braking Systems: Knowing the difference between disc and drum brakes, and how hydraulic pressure is used to apply braking force.
- Steering and Suspension: Recognizing components like tie rods, shock absorbers, and control arms, and understanding their role in vehicle handling and ride comfort.
- Basic Electrical Circuits: Understanding voltage, current, and resistance; being able to trace a simple circuit (battery, switch, bulb) and use a multimeter to test continuity.
Exam Tips & Revision Strategies
- Before starting, always refer to the vehicle handbook or door pillar sticker for correct pressures, and check tyres only when cold for accurate readings.
- When demonstrating tread depth measurement, explain the legal limit and show awareness that tyres must be checked across the full width and circumference, not just in one location.
- Maintain a safe working posture and ensure the vehicle is on level ground with the parking brake applied before any maintenance activity.
- If asked to top up air, show competence by adding small bursts, re-checking pressure each time to avoid over-inflation, and clearly confirm when the target pressure is reached.
- Always refer to the vehicle manufacturer’s recommended pressures, not the maximum pressure on the tyre sidewall.
- Use personal protective equipment (PPE) such as gloves and eye protection when handling tyres and tools.
- Remember that a tyre at the legal limit of 1.6 mm performs significantly worse in wet conditions than one with deeper tread.
- During assessments, verbally explain each step to demonstrate understanding, even if the task is practical.
Common Misconceptions & Mistakes to Avoid
- Learners often check tyre pressures when tyres are hot, leading to inaccurate readings due to thermal expansion; assessment should ensure checks are on cold tyres.
- Confusing psi and bar units, resulting in over- or under-inflation.
- Measuring tread depth only on one spot rather than checking for uneven wear across the tyre, potentially missing illegal tread in other areas.
- Failing to securely replace the valve cap, which can lead to slow air loss and contamination.
- Using a damaged or uncalibrated pressure gauge without checking its zero point first.
- Reading the pressure gauge incorrectly, especially with analogue dials.
Examiner Marking Points
- Award credit for correctly identifying the manufacturer’s recommended tyre pressure for the vehicle and demonstrating how to locate this information.
- Assessor must observe the learner safely using a calibrated pressure gauge and accurately reading the pressure to within ±1 psi of the recommended level.
- Evidence must show the learner using an appropriate air source and achieving correct inflation, followed by re-checking with the gauge.
- Credit to be given for correctly measuring tread depth across the central three-quarters of the tyre width and around the full circumference, recording results in millimetres.
- Learner must demonstrate awareness of the legal minimum tread depth (1.6mm) and identify any tyres that fail to meet this standard.
- Award credit for selecting the appropriate pressure gauge or airline connector without prompting.
- Ensure the learner correctly positions the pressure gauge on the valve stem and obtains a stable reading.
- Look for the proper use of a tread depth gauge, including checking across the central three-quarters of the tyre.