Interpretation ID: aiam2389
Vice President
Advanced Programs
Rockwell International
2135 West Maple Road
Troy
MI 48084;
Dear Mr. Rodger: This responds to Rockwell International's February 23, 1976, reques for confirmation that the deactivation of automatic adjusters is acceptable during burnish procedures of Standard No. 121, *Air Brake Systems*, at the option of the manufacturer.; The procedure that you recommend is not permitted by any provision o Standard No. 121. The NHTSA would consider some provision to deal with the overadjustment of automatic adjusters upon receipt of technical data showing justification for such action. Based on consideration of the data received and a petition for amendment, the agency could commence a rulemaking proceeding in accordance with established procedures.; It should be noted that the option in FMVSS 105-75 that you describ requires that the automatic adjusters be deactivated for the entire test sequence, not just the burnish procedure.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs;