Federal Motor Vehicle Safety Standards; Air Brake Systems; Long- Stroke Brake Chambers

Consistent with a recommendation by the National Transportation Safety Board and in response to a petition for rulemaking from the American Trucking Associations (ATA), this final rule amends the reservoir requirements in Standard No. 121, Air Brake Systems, for trucks, buses, and trailers equipped with air brakes. The agency believes that the amendments will improve the braking efficiency of such vehicles and reduce the number of brakes found to be out of adjustment during inspections. It will do this by removing a design restriction that tends to discourage the use of long-stroke brake chambers, a technology with potentially significant safety benefits.