UN R90 — Supplement 5 to the 02 series of amendments

The braking system must be tested to the requirements for the vehicle category in question in UN Regulation No. 78, Annex 3, paragraph 1. Paragraph 2.1.1. now lists the categories L1, L2, L3, L4, L5, L6, L7. Before, the list was L1, L2, L3, L4 or L5.

Paragraph 2.1.1.1. is now the "Dry stop test - single brake control actuated", not the "Type-0 test with engine disconnected". The test is done only in the laden condition, with one brake application under Annex 3, paragraphs 3.1. and 3.2., of UN Regulation No. 78. It goes up to wheel lock, the deceleration required by Annex 3, paragraph 3.3. of UN Regulation No. 78, or the maximum allowed control force. Where approval is required for front axle brakes, the test is on the front brakes only; for rear axle brakes, on the rear brakes only. New paragraph 2.1.1.2. is a "Dry stop test – all service brake controls actuated" under Annex 3, paragraph 4., UN Regulation No. 78 requirements. A deleted paragraph asked for a minimum of six brake applications at spaced increments of control force or line pressure.

Paragraphs 2.1.1.3., 2.1.1.4. and 2.1.1.5. are now the "High speed test", the "Wet brake test" and the "Heat fade test". The high speed test is only applicable for vehicles of categories L3, L4, L5 and L7. It is carried out under Annex 3, paragraph 5., UN Regulation No. 78 requirements. The wet brake test follows the requirements in Annex 3, paragraph 6. of UN Regulation No. 78. The heat fade test follows the requirements in Annex 3, paragraph 7. of UN Regulation No. 78. Before, paragraphs 2.1.1.2., 2.1.1.3. and 2.1.1.4. were the "Type-0 test with engine connected", the "Type-0 test with wet brakes" and the "Type-I test".

The cold performance comparison with the original brake lining assembly now uses the test results, not the Type-0 test results of paragraph 2.1.1.1. New paragraph 2.2.1.1. asks for a minimum of six brake applications at spaced increments of pedal effort or line pressure. They go up to wheel lock or, alternatively, up to the minimum mean fully developed deceleration of Annex 3, paragraph 3.3., UN Regulation No. 78. The other option is up to the allowed maximum pedal force for the category of vehicle in question. The initial speed is as given in Annex 3, paragraph 3.2., UN Regulation No. 78. New paragraph 2.2.1.2. asks to note and plot pedal force or line pressure and mean fully developed deceleration for each application.

The speed sensitivity test is now only applicable for vehicles of categories L3, L4, L5, and L7; before, L7 was not in this list. It is carried out with the laden vehicle under the test conditions defined in Annex 3, paragraph 3.1. and 3.2. of UN Regulation No. 78. Before, it used the conditions of the Type-0 test with engine disconnected. Paragraph 2.2.2.1. now takes the control force or line pressure from the cold performance test results of paragraph 2.2.1.1., not the Type-0 test. The minimum required mean fully developed deceleration in that paragraph is now as described in Annex 3, paragraph 3.3 of UN Regulation No. 78. Paragraph 2.2.2.2. no longer says "and with initial brake temperature ≤ 100 °C".

Paragraph 1.3. now refers to a combined braking system in the meaning of paragraph 2.6. of UN Regulation No. 78. Before, it referred to paragraph 2.9. of Regulation No. 78. Paragraphs 1.1., 2.1. and 2.1.2. now say "UN Regulation No. 78" instead of "Regulation No. 78".