Regular parking brake maintenance important for heavy vehicle owners


Early detection of possible brake maintenance issues in heavy vehicles is at the forefront of a Waka Kotahi NZ Transport Agency change to the vehicle inspection requirements manual (VIRM) for Certificate of Fitness (CoF) inspectors.

Owners of heavy vehicles may be asked by a CoF inspector to provide a 4085D form(external link) if the inspector is uncertain whether the park brake assembly has been recently serviced. The form requires the owner or operator of the vehicle to confirm the assembly has been inspected, and serviced if needed, by a technician in the last two years and is in good working condition. 

This change to the VIRM has resulted from several runaway vehicles that have led to crashes after after the park brake was applied. 

A park brake application valve beside the driver’s seat on many trucks, buses and motorhomes has been identified as the issue, as the valve wears out internally through dust and moisture getting in over time and causes operational problems. 

If the lack of maintenance on the park brake assembly is the only item preventing the vehicle from being issued a CoF, the vehicle inspector can issue a 28-day permit to allow the operator to have the parking brake maintenance carried out and the form completed. 

A vehicle must still pass a parking brake performance test, such as a roller brake test or stall test, as part of the regular CoF inspection. If it fails the performance test, the owner must address further issues with the parking brakes and also have a 4085D form completed to provide proof of maintenance. 

The Transport Agency’s message to heavy vehicle owners is to make sure your vehicle’s park brake assembly is regularly serviced. This is for the safety of the drivers of these vehicles, other road users and pedestrians who are around heavy vehicles. 

CoFs and Warrants of Fitness are a snapshot in time of a vehicle’s condition, and regular maintenance is the best way to ensure your vehicle’s safety between inspections.