Pre-trip defects against a dispatch deadline
At 05:10 in summer, a driver begins a pre-trip inspection of a 6x4 rigid truck loaded to 24 t for a 600 km run. Forecast is 46°C. He finds: a 5 cm sidewall bulge and 2.8 mm tread on the front-left steer tyre; with the engine running, air pressure builds from 0 to 6.8 bar in 6 minutes; with the engine off it falls from 6.8 to 5.6 bar in 5 minutes; the drive-axle brake pushrod stroke is 58 mm against a manufacturer limit of 45 mm; coolant is at the minimum mark; the reverse light is out; the wiper blade is torn. The spare tyre is serviceable but the driver has no torque wrench and the yard fitter has gone home. The dispatcher says the load must leave now to avoid a penalty. The truck's defect book is in the cab.
1. Sort the findings into immediate no-go defects and defects that can be deferred only after assessment. Give reasons.
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Immediate no-go: the front-left steer tyre has a 5 cm sidewall bulge and only 2.8 mm tread. A sidewall bulge means internal cord damage and can burst at speed; a steer tyre failure is especially dangerous. The air system loses 1.2 bar in 5 minutes with the engine off, which is a significant leak and leaves insufficient reserve for repeated braking; it must be traced and repaired. The drive-axle pushrod stroke is 58 mm against a 45 mm limit, indicating excessive slack or brake adjustment; braking performance and spring-brake travel are compromised. Coolant at minimum, a failed reverse light and a torn wiper are defects that must be recorded and corrected, but they do not by themselves justify moving a truck with the first three defects. The vehicle must not leave until the tyre, air leak and brake stroke are repaired and re-inspected.
2. Can the driver fit the spare tyre himself and adjust the brakes to save time? Explain the risks and limits.
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No. Changing a steer tyre without a torque wrench and without correct torque procedure risks wheel nuts loosening or being over-tightened, damaging studs and the wheel. The spare has not been inspected for age, pressure or damage, and a roadside fit is not a proper repair. Brake pushrod stroke is not a matter of guessing: adjusting a slack adjuster without checking chamber condition, foundation brake wear and manufacturer procedure can leave the brake dragging or under-performing, and the pushrod may be at the limit because of internal chamber or linkage faults. The driver should report the defects, request a fitter or recovery, and not sign a release or falsify the defect book. A penalty for late departure is less serious than a steer tyre burst, a brake failure or an air-loss incident on a 600 km run in 46°C heat.
3. Describe the correct defect-reporting and release process before the truck is used.
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The driver should enter every defect in the defect book with time, mileage, description and his name, including the tyre bulge, tread reading, air-pressure drop, pushrod stroke, coolant level, reverse light and wiper. He should notify the dispatcher and the workshop in writing or by recorded phone call, and state clearly that the vehicle is not to be released. The fitter should repair or replace the tyre, trace and repair the air leak, adjust or repair the brake mechanism, top up coolant and fix the lights and wiper. After repair, the driver should carry out a fresh pre-trip check, including a leak test and brake test, and only then sign the release. If no fitter is available, the vehicle stays parked and the load is delayed or transferred. The defect record must remain accurate; a false 'nil defects' entry can expose the driver and company to serious legal and insurance consequences.