NZ CoF Inspector cheat sheet

A Certificate of Fitness is the periodic inspection and certification document for heavy vehicles; light vehicles use the Warrant of Fitness instead.

CoF inspection frequency for heavy vehicles is generally every 6 months, with some vehicles eligible for 12-month intervals where permitted by the applicable rule.

A CoF certifies the vehicle met the prescribed in-service standards at the time of inspection; it is not a warranty of continued roadworthiness.

Inspection must cover the prescribed items: brakes, steering, suspension, tyres, wheels, lights, glazing, body and chassis condition, and towing connections where fitted.

A vehicle that fails inspection must not be certified; defects must be recorded and the vehicle either repaired and re-presented or failed with the reasons stated.

Modifications affecting structural strength, braking, or lighting require verification against applicable standards before certification can be given.

The inspecting organisation must be authorised; only a person holding the appropriate inspection designation may inspect and certify.

Load security, conspicuity (where required), and exhaust condition are part of the pass/fail decision for heavy vehicles.

A CoF label is affixed to the vehicle showing the expiry date; operation beyond expiry is an offence.

Chassis rails must be free of cracks, significant corrosion, and unauthorised welding or repair that reduces section strength.

Cross-members, gussets, and body mounts must be present, secure, and free of cracks or fatigue failure.

Steering components (drag links, tie rods, kingpins, ball joints) must have no excessive free play, binding, or visible damage.

Suspension springs must not have broken leaves, cracked main leaves, or missing/shifted U-bolts; airbags must not leak or show sidewall damage.

Wheels must be free of cracks, distortion, and loose or missing fasteners; stud holes must not be elongated.

Tyres must meet tread depth minimums, be free of exposed cords, bulges, and sidewall damage, and be matched appropriately across an axle.

Fifth wheel and kingpin assemblies must be secure, correctly lubricated, and free of excessive wear or cracks.

Structural repairs must be carried out to an accepted standard and, where required, be verified by a qualified person before certification.

Exhaust systems must be secure and not leak into the cab or pose a fire risk; fuel and air lines must be secure and free of chafing.

Heavy vehicles must have service brakes operating on all wheels and a parking brake capable of holding the vehicle on a gradient.

Brake performance is assessed against prescribed deceleration or stopping-distance criteria for the vehicle class, not merely 'brakes feel okay'.

Air brake systems must build pressure within specified limits, hold pressure without excessive leak-down, and have functioning low-pressure warning.

Spring (parking) brakes must apply automatically on loss of air pressure and release correctly when pressure is restored.

Brake linings and pads must have sufficient friction material remaining and be free of contamination by oil, grease, or fluid.

Brake drums and discs must not be cracked, deeply scored, or worn beyond manufacturer limits; hoses and lines must not leak or be damaged.

An air loss rate test and a brake balance check across axles are part of a competent heavy-vehicle brake inspection.

Anti-lock braking systems, where fitted, must have no active fault warning and must function correctly.

Trailer brakes must operate in sympathy with the towing vehicle, including correct coupling of the air or hydraulic connection.

Every inspection must be recorded, including pass/fail outcome, items inspected, and any defects identified.

Records must be retained for the period required by the applicable rule and be available for audit by the regulating authority.

The inspector must record the vehicle identification (VIN or chassis number), odometer reading, and inspection date.

Certification must only be issued by an authorised inspector acting within their scope of designation; certifying outside that scope is a breach.

Defects that make a vehicle unsafe must be recorded and the vehicle failed; the inspector must not certify a vehicle they know to be unsafe.

Inspectors must be independent and free of conflicts of interest; they cannot certify a vehicle they have a financial interest in repairing without disclosure.

The CoF label and any documentation must match the vehicle inspected; misrepresentation of inspection results is an offence.

Where a vehicle is failed, the reasons must be communicated to the operator and retained in the inspection record.

Inspectors have an obligation to report suspected odometer tampering or fraudulent documentation to the appropriate authority.