Proposal to clarify the intent of the selected paragraphs to ensure that systems with with one service brake meet braking performance requirements using only that brake system (i.e, without any assistance from the secondary brake system). There had been an interpretation that for systems with two service brakes each brake had to meet the requirements which would result in higher stringency levels than intended by the requirement for single brake systems.
The proposal also clarifies the parts of the braking system that should be considered with respect to hydraulic brake and mechanical transmissions and further clarifies that the test procedures are designed to simulate a brake failure rather than produce one.
20. The expert from IMMA introduced ECE/TRANS/WP.29/GRRF/2014/5 and ECE/TRANS/WP.29/GRRF/2014/6 as amended by GRRF-76-19 and GRRF-76-36-Rev.1 proposing general clarifications to UN Regulation No. 78 and specific clarifications for the use of Combined Braking Systems (CBS). The proposals received some comments and the expert from IMMA consolidated these requested changes into a revised proposal (GRRF-76-45). The expert from India introduced GRRF-76-32 on three wheelers, which GRRF agreed to revisit on the basis of a revised proposal at its September 2014 session. GRRF requested the secretariat to distribute GRRF-76-45 with an official symbol at the September 2014 session.