Defect Identification, Roadworthiness Obligations, and Regular Mechanical Inspections

What counts as a defect under the HVNL

Under HVNL s527, a heavy vehicle is a defective vehicle if it:

• does not comply with the heavy vehicle standards (ADRs and the Heavy Vehicle (Vehicle Standards) National Regulation), or
• has a part that does not perform its intended function, or
• has a part that has deteriorated to the point it can no longer be relied on.

The National Heavy Vehicle Inspection Manual (NHVIM V3.1, December 2024) is the nationally consistent inspection manual used by authorised officers, approved vehicle examiners, and Licensed Vehicle Testers to decide whether a part meets those tests. It is the technical reference behind every defect notice issued in Victoria.

The three NHVR defect-notice categories

When an authorised officer (a NHVR Safety and Compliance Officer, a Victoria Police member, or a VicRoads officer) finds a defect, they issue one of three notices. The category reflects the safety risk, not the cost or size of the repair.

A major defect requires immediate withdrawal from service. The vehicle cannot be driven on a road (except to a repair location as stated in the notice or by tow/transport). Using or permitting the use of a heavy vehicle in contravention of a defect notice is a separate offence.

Concrete defect examples and how to classify them

The examples below come from the NHVIM failure criteria and are the kind of defect the Victorian Heavy Rigid knowledge test asks you to classify.

Tyres and wheels (NHVIM Section 5)

• Cracked wheel rim — a crack in a rim is a major defect. The rim has lost structural integrity and can fail catastrophically; the wheel must not be driven on.
• Loose or missing wheel nuts — a loose wheel nut is a major defect; a missing wheel nut is a major defect. Look for rust streaks radiating from a stud, which show the nut is backing off.
• Tyre with exposed cords or wire — major defect. The tyre has lost its protective tread and can shed tread or burst.
• Tread depth below 1.5 mm in the principal groove across 75% of the width — defect (treated as safety-related; do not drive).
• Bulge, bump, or ply separation — major defect. The carcass is failing.
• Dual tyres in contact — defect; heat build-up between the tyres can cause a blow-out.

Brakes (NHVIM Section 2)

• Air leak that drops reservoir pressure below the warning threshold with the engine off — major defect. The system cannot hold pressure; the spring brakes may apply while moving.
• Brake lining (friction material) below manufacturer's minimum thickness (or within 3 mm of the mounting surface for bonded pads) — major defect. Lining capacity is insufficient for a full-service stop.
• Friction material contaminated with oil, grease, or brake fluid — major defect. Contaminated lining has reduced friction and can fail without warning.
• Brake hose cracked, bulging, or leaking — major defect. The hose can rupture under pressure.
• Inoperative service brake — major defect. The primary means of stopping the vehicle has failed.
• ABS warning lamp stays on — minor defect (the service brake still works, but ABS is disabled). The vehicle can be used under conditions until cleared.
• Brake pedal anti-slip surface missing or broken — minor defect unless it prevents safe operation.

Lights and reflectors (NHVIM Section 8)

• Headlight not working (low or high beam) — defect; the vehicle does not meet lighting standards. A single failed headlight is a minor defect; both failed is a major defect because the driver cannot see and other road users cannot see the vehicle at night.
• Brake lights inoperative — defect; rear-end collision risk.
• More than 30% of LEDs failed in a single assembly — defect; the assembly is no longer performing its intended function.

Steering and suspension (NHVIM Section 4)

• Steering component cracked, broken, or loose — major defect; loss of directional control is possible.
• Excessive steering wheel free play beyond the manufacturer's limit — defect; steering response is degraded.
• Suspension component loose, cracked, or missing — major defect; vehicle stability is compromised.

What a driver must do when a defect is found

The driver's obligations are set by the Primary Duty under HVNL s26C and by the general duty to use a roadworthy vehicle:

1. Stop and assess. If the defect is found on the road, pull over safely. If it is found during the daily check, do not depart.
2. Classify. Use the NHVIM criteria above. If in doubt, treat the defect as major.
3. Record. Note the defect on the daily-check sheet or in the defect-reporting system your operator uses. A verbal report is not enough under most operator management systems.
4. Repair or withdraw. A major defect means the vehicle is withdrawn from service and either repaired on site, driven only to a repair location as a defect notice allows, or towed/transported.
5. Notify the operator. The operator (and other CoR parties where relevant) must be told so the defect can be cleared and the maintenance system updated.

Driving a vehicle with a known major defect — even a short distance to 'get back to the depot' — is a Primary Duty breach under HVNL s26C. Maximum penalties (from 1 July 2025) are $424,794 or 5 years imprisonment or both for an individual and $4,113,837 for a corporation.

Victorian roadworthiness obligations and defect clearance

In Victoria, heavy vehicle defect clearance is handled through 'HV' Licensed Vehicle Testers authorised by VicRoads. The clearance process depends on where the defect was issued and where it is cleared:

• Defect issued in another jurisdiction, cleared in Victoria: the vehicle is presented to an 'HV' Licensed Vehicle Tester. If a full inspection is required, the tester carries out a complete roadworthy inspection and issues a Certificate of Roadworthiness.
• Defect issued and cleared in another jurisdiction: a Victorian roadworthy or VicRoads inspection is not required; the defect notice must be signed by an authorised clearance-station inspector from the issuing state.
• Defect issued in Victoria, cleared in another jurisdiction: a current Certificate of Roadworthiness from any jurisdiction must be presented at a VicRoads Customer Service Centre; a VicRoads inspection is not required.

Failure to clear a defect notice can lead the registration authority to suspend or cancel the vehicle's registration.

Regular mechanical inspections

The daily check catches defects that develop between services. Scheduled (programmed) maintenance is what keeps the vehicle within the heavy vehicle standards over its service life. The operator sets the inspection intervals in the maintenance schedule, informed by the manufacturer's service intervals, the operating conditions, and any NHVR or VicRoads inspection requirement.

Key points the Victorian Heavy Rigid test expects you to know:

• The operator must have a maintenance system. Under HVNL and the NHVR Master Industry Code of Practice, a registered operator must have a documented maintenance system that schedules inspections, records repairs, and tracks defects. The driver's daily check is part of that system.
• Inspection intervals are set by the maintenance schedule, not by a fixed statutory interval for every vehicle. Intervals are based on kilometres, hours, or time (whichever comes first) and on operating conditions — off-road or dusty work shortens intervals.
• Annual / periodic inspections. Some jurisdictions run programmed (annual) heavy vehicle inspections. Victoria does not require a blanket annual roadworthy for all heavy vehicles, but a Certificate of Roadworthiness is required when a defect notice requires a full inspection, when a vehicle is sold in some circumstances, and when an operator's accreditation or a particular notice requires it.
• NHVIM is the inspection standard. When an inspection is carried out, the criteria are the NHVIM V3.1 failure criteria (NHVIM V3.2 applies from 1 August 2026). The same manual is used by authorised officers on the roadside and by Licensed Vehicle Testers in the workshop, so a part that passes a workshop inspection should also pass a roadside check.
• The driver is part of the system. A driver who completes the daily check, records defects, and refuses to drive a vehicle with a major defect is meeting their Primary Duty. A driver who skips the check, does not record a known defect, or drives a defective vehicle to save time is breaching the Primary Duty and can be prosecuted personally.