Pre-Trip Check on a Loaded Diesel Truck at -3 °C

Stop-the-truck items (do not depart):

1. Spongy pedal with fluid at MIN. Increased travel of 30 mm means air or a leak in the hydraulic circuit. In a panic stop, or after repeated use on a long descent with 900 kg aboard, the pedal can go to the floor. This is the single most dangerous finding - find the leak (lines, calipers, wheel cylinders), repair and bleed.
2. 20 mm sidewall bulge. A bulge means broken internal cords; it cannot be repaired and can burst without warning, especially cold, loaded, on a mountain road. Replace it, ideally as an axle pair.

Fix before departure (lower risk, but not optional):

• Tyres at 29–32 psi against 35 - underinflation adds sidewall flex and heat; inflate to specification.
• Tread 2.4 mm is legal (limit 1.6 mm) but the margin is thin for a loaded winter run; log it for replacement soon.
• Oil at MIN and coolant at LOW - top up cold, then recheck after 20 km for a leak; running at MIN on a climb risks oil starvation and overheating.
• Washer empty and iced - you need visibility behind a salt-spraying truck; fill with proper low-temperature fluid, never plain water.

Verdict: the brake fault and the bulged tyre are crash causes, not breakdowns. The truck does not leave until both are fixed.

Tyre rules: the legal minimum tread depth is 1.6 mm, measured in the principal grooves. A sidewall bulge, exposed cord or a repair in the sidewall fails the 자동차 정기검사 regardless of tread depth, because it is a structural defect, not a wear item.

Inspection: the sticker expired 12 days ago, so the vehicle is being driven outside its valid inspection period. That exposes you to 과태료 that increases the longer it is delayed, and in serious or repeated cases to an order stopping the vehicle from being operated. An accident while uninspected also complicates the insurance position and the other party's arguments.

Why it is not just paperwork: the periodic inspection tests exactly the systems you just found wanting - brakes on a roller tester, tyre condition, lights, steering play, exhaust. In practice, the correct sequence here is: repair the brakes and the tyre, inflate the rest, top up the fluids, then present the truck for the overdue inspection, and treat the inspection result as an independent check on your own judgement.

One more legal point: a 900 kg load must be secured with rated straps and distributed within the axle limits - an unsecured load is itself an offence and changes the braking behaviour of the truck.

What the DPF does: the diesel particulate filter traps soot and burns it off when exhaust temperature is high enough - regeneration typically needs 20–30 minutes of steady driving at roughly 60–80 km/h, or a manufacturer-initiated service regeneration.

Why today's route is bad: 20 km of low-speed mountain climbing at -3 °C gives low exhaust temperature, a cold engine and heavy load - the exact conditions that produce soot faster than the filter can burn it. A steadily lit DPF lamp means regeneration is being requested; if it starts flashing, the vehicle is heading for limp-home mode. Forcing it by revving in neutral does nothing, because there is no load and therefore no heat.

Practical plan: complete the brake and tyre repairs, then take a 30-minute steady-speed run rather than the mountain route. If the lamp does not clear, go to a service centre - do not ignore it, since a clogged filter means a tow and a very expensive replacement.

Idling and fuel: idling does not regenerate a DPF and burns roughly 0.5–1 L per hour on a diesel of this size; it also produces the cold, sooty exhaust the filter is trying to trap. Warm up by driving gently, switch off during stops, and use the specified low-ash engine oil - the wrong oil ash-loads the filter permanently.