Proposal to insert new paras. 3.3.29. to 3.3.33. defining “Semi-Metallic-Organic,” “Low-Steel-Organic,” “Non-Asbestos-Organic,” and “Low-Steel-Non-Organic” friction materials and “Pad area,” amend Annex 2 title to read “Annex 2 Communication,” insert a new footnote to Annex 2, and insert a new Annex 2 – Appendix containing a list of vehicle data for UN Regulation No. [XXX] approvals including vehicle type description, brake linings and discs specifications, vehicle test mass, maximum speed, tyre dimensions, brake circuit configuration, and brake specifications.
This document proposes a new UN Regulation on uniform provisions concerning approval of non-original and identical replacement brake parts regarding particulate emissions. The regulation applies to laboratory measurement of brake emissions from non-original replacement brake pads, linings, discs, and drums for vehicles of categories M₁, N₁, and N₂ originating from vehicles with type approval under Regulation No. 179. Approval requires emission factors to comply with specified limits based on vehicle category and powertrain technology. The regulation establishes brake emissions families based on characteristics including calliper type, vehicle axle location, friction material formulation, brake disc or drum material, disc surface form, friction material surface area, and drum diameter. Testing procedures, conformity of production requirements, marking and packaging specifications, and approval extension procedures are detailed.
Task Force 3b addresses vehicles with limited speed by introducing a new Appendix 3 in Annex 4 to calculate adjusted cycles when vehicle maximum speed is lower than the WLTC-Brake cycle. The proposal modifies brake corner emissions family testing to allow vehicles with limited speed to be included in families with standard vehicles, with emission factors calculated from parent family factors or measured on adjusted cycles. Amendments address c-factor measurement, cycle-adjusted brake events, kinetic energy dissipation tolerances, and report file specifications.
Draft Minutes of the 56th Particle Measurement Programme session held online on 9th July 2026, 12:00-14:30 CET. The meeting reviewed amendments to Brakes GTR 24 and UN R179 across five task forces. TF3a presented layout and testing topics with concerns raised regarding repetition increases and force distribution. TF3b discussed vehicles with limited speed and family classification issues. TF3c addressed brake replacement parts and emission limits. TF4 reported on electromechanical brakes with work package B agreed. TF5 presented the GTR on heavy-duty brake particle emissions with results expressed in mg/km, with some points remaining in brackets pending inter-laboratory comparisons. Comments are due by 16th July, with the next meeting expected mid/end of September 2026 and a hybrid PMP meeting planned for 12th or 13th October in Geneva.
Task Force 5 progressed toward GTR adoption planned for GRPE 95th session in 10/2026. JRC endurance braking tests conclude 07/08/2026. A small round robin exercise with six participants tests three airflow settings to finalize bracketed values. Key updates include maximum sampling probe length of 1.35m, PM10 probe positioning on outside streamline for bent layouts, and probe distance reduction from 100mm to 70mm. Proposal to delete the Disc or Drum Metallurgy for Brake Groups section. Final GTR text requires PMP comments by 22/07/2026, with layout decisions by 16/07/2026. UNR drafting based on UN R179 skeleton has commenced with significant work required.
Proposal to amend UN R179 following GRPE-94-15e:
TF 3c addressed brake emission of replacement parts. Proposed amendments include clarification that surface heat-treated discs fall under “other” category, refinement of “Brake Emissions Family Parent” definition, and addition of new appendix to UN Regulation No. 179 Annex 2. Data sharing agreement established: front-to-rear axle emission ratio, brake force distribution, and vehicle electrification type will be shared with aftermarket operators. Two approaches for aftermarket applicants: use vehicle-specific data through benchmarking or bilateral agreements, or apply default values from Tables 5.4 and 5.5. Testing revealed up to 30% variation within friction-couple families. Safety factor application when using actual c-factor values remains under discussion, with final decision expected before October.
Task Force 4 has completed revisions to GTR 24 concerning electro-mechanical calipers and proposes to include them in Amendment 3.
10. The secretariat recalled the mandate extension until February 2019 of the IWG on Modular Vehicle Combinations (MVC) adopted by WP.29 in March 2017.