New regulations on replacement truck brake discs

It is now more than 15 years since the European safety regulation, ECER90, was introduced for replacement disc brake pads and drum brake linings.

The aim of ECER90 was to establish a common minimum standard of braking performance, product integrity and manufactured quality, for replacement brake linings across the whole of Europe. Prior to the introduction of ECER90 the market was unregulated and products of dubious performance and quality could be sold with impunity with consequent safety risks to all road users.

Once ECER90 had been implemented and “bedded down” for brake linings, the GRRF in Geneva – the the body responsible for preparing regulatory proposals on active safety, in particular brakes and running gear, for the World Forum for Harmonisation of Vehicle Regulations – WP29), turned their attention to the other element of the braking couple, the brake disc and drum.

These too are safety critical components with hitherto no regulatory standards to control their performance, integrity or manufactured quality. A working group was therefore formed from experts at vehicle, and brake component manufacturers and government technical services across Europe, to develop an extension to ECER90 to cover brake discs and drums.

The outcome of five years of vigorous discussion and testing, finally resulted in the 2002 series of amendments to ECER90, to include brake discs and drums for vehicles in the categories M, N and O (all classes of motor vehicles other than motor cycles).

The 02 series of amendments will come into force across Europe as a consequence of Article 6 of another piece of legislation called the General Safety Regulation (GSR) and initially it will be applied to replacement brake discs for vehicles in categories M2, M3, N2, N3, O3 & O4, basically trucks, buses and trailers, whose brake systems are type approved after 1/11/2014.

For brake drums for these vehicle categories the date will be 1/11/2016. Similarly for all other categories of vehicles the requirement will apply to replacement brake discs and drums whose brake systems are type approved from 1/11/2016.

Consequently existing part numbers need not be approved from a legal standpoint, only parts for vehicles released onto the market after the prescribed dates; that said there is clearly merit in being able to demonstrate to the market place that the replacement parts you sell today will meet the new legislative requirements and that is exactly what Juratek has decided to do.

Consequently the existing Juratek range of CV brake discs are now undergoing approval by the UK VCA such that by 1/11/2014 over 95 per cent of the current range of Juratek CV brake discs will be approved to UNECER90:02.

So what does approval entail and how does it help ensure improved product quality & safety? The following table will help explain and illustrate the concept relative to that for brake linings.

The approval for replacement brake discs and drums follows the same general concept as for replacement brake linings; there are performance tests to check that the replacement part meets the requirements of Regulation 13 (CV) or 13H (Cars).

This is the braking regulation that all new vehicles must meet before they can be sold on the market, and a performance comparison with the OE fitment, where in the case of replacement brake discs and drums the requirement is the replacement part should have a similar performance within 8 per cent of the OE part that it is replacing.

Then there are Structural Integrity tests. These tests, in particular the Thermal Fatigue test, really lie at the heart of ECER90:02 for replacement brake discs and drums and are designed to ensure that replacement parts at least match the capability of OE parts in dissipating high levels of braking energy without excessive cracking or structural failure.

As with brake linings replacement brake discs and drums will carry the “E” approval mark which will be of the following general form (for example) E11 02 C 0359 7248”, “E11” indicating approval by the UK, 02 the series amendment, “C” a brake disc (“D” for a brake drum), and the first series of digits the manufacturer and the “type” (basic design & material composition) and the second series of digits the “variant” (specific dimensions).

The Conformance of Production or CoP is the means of ensuring the delivered quality of each production batch. In the case of replacement brake discs and drums this means that the chemical composition of the iron and the tensile strength and hardness of each production batch has to be measured, recorded and compared on a statistical basis with the reference values registered with the Approving Authority at the time approval was first sought.
This extension to ECER90 is welcome.

Like brake pads and linings brake discs and drums are safety critical parts and the extension of the regulation will help ensure that only replacement brake discs and drums of a high level of quality are sold and used, and that can only be of benefit to all owners, operators and road users.