Braking compatibility

With Australian designed and built trucks as well as fully imported trucks from Europe, the USA, Canada and Japan in the market; the Australian trucking industry is home to a diverse range of vehicles. While this diversity ensures competitiveness, it also results in many challenges – one of the most notable being braking compatibility of heavy vehicle combinations.

Issues with poor braking performance, poor braking stability and excessive pad/lining wear have been plaguing the industry for decades. The causes of these problems include different braking standards, poor setup of the braking system and the use of improper parts for in-service replacement.

“Trucks and trailers manufactured in Europe are built to United Nations Economic Commission for Europe (ECE) – Regulation 13 braking requirements. Japanese trucks are also typically built to ECE-R13. North American built vehicles must comply with either US FMVSS-121 or its close cousin Canadian CMVSS 121. Australian-built trucks comply with ADR-35/02 and Australian-built trailers with ADR-38/03,” explained Knorr-Bremse Senior OEM Application Engineer, Robert Smedley.

He said the key differences with ECE Regulation 13 vehicles is that they have adaptive braking systems, using load sensing brakes with ABS or EBS; and that the wheels on a rear axle must not lock-up earlier than wheels on a front axle, thus resulting in more powerful front axle brakes.

“European trucks meet the (ECE compatibility) limits. Australian trucks meet the limits only when they have a Load Sensing Brake Function (LSF),” said Mr Smedley.

“If Australia were to adopt the ECE-Reg 13 limit curves there would be improved brake compatibility between trucks and trailers. The benefits of improved braking balance are shorter stopping performance of vehicle combinations, better directional stability during heavy braking and more even brake wear.

“Australia is now part of the electronic braking control revolution,” he said. “An Electronic Brake Control System (EBS) may now manage the braking. It knows all the sensed wheel speeds, the steering wheel direction and the lateral (yaw) acceleration. An Electronic Stability Control System (ESC) to correct poor directional control during braking can now be made automatically.

“With the advent of multi-volt trailer EBS also came dual load sensing functions. The trailer EBS can be set up to automatically match the trailer braking performance to both a truck without adaptive brakes (North American or Australian) or a truck with adaptive brakes (European or Japanese). This is ideal for fleets with a mix of both European and American type trucks.”