Vehicle Technical Knowledge and Roadworthiness for Category C
Core concepts
Category C candidates must understand the systems they inspect daily: braking (service, parking and auxiliary/retarder), steering, suspension and air suspension, tyres (tread depth, pressure, load index, damage, twin-tyre matching), lighting and signalling, the air system (compressor, reservoirs, drain valves, low-pressure warning), and the coupling mechanism (fifth wheel, kingpin, safety catch). Know the daily walk-around check: tyres, lights, mirrors, fluid levels, air pressure build-up, brake test, load security, and the tachograph. Roadworthiness is verified by periodic technical inspection (ГТП) with a sticker and certificate, plus roadside checks. Know the maximum permitted tread wear, the meaning of the ABS warning lamp, and what to do if the air-pressure warning sounds while driving.
Traps in questions
A classic trap is the ABS lamp: it means the anti-lock function is disabled, but normal brakes still work - you may continue to a workshop, not necessarily stop immediately, unless the red brake warning is also on. Another trap is twin tyres: mismatched diameters cause overheating and premature failure. Questions also test that a low air pressure warning requires stopping safely, and that the parking brake must hold the vehicle on a gradient. Do not confuse the retarder with the service brake.
Worked example / rule of thumb
Rule of thumb: "Red = stop, amber = check soon." Example: an amber ABS lamp appears on a dry road. Normal braking remains, so you may drive carefully to a workshop; if a red brake-circuit lamp appears at the same time, stop immediately and do not continue.