haulrecordFMCSA data

Violation codes / 393.53B-B

49 CFR 393 · Parts and accessories

393.53B-B

What it means

Air Brake - CMV manufactured on or after 10/20/1994 has an automatic airbrake adjustment system that fails to compensate for wear

What the rule actually says

This violation cites 49 CFR 393.53, automatic brake adjusters and brake adjustment indicators. The regulation reads:

(a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake system, shall meet the automatic brake adjustment system requirements of Federal Motor Vehicle Safety Standard No. 105 (49 CFR 571.105, S5.1) applicable to the vehicle at the time it was manufactured.

(b) Automatic brake adjusters (air brake systems). Each commercial motor vehicle manufactured on or after October 20, 1994, and equipped with an air brake system must meet the automatic brake adjustment system requirements of Federal Motor Vehicle Safety…

The section continues.

49 CFR 393.53, Automatic brake adjusters and brake adjustment indicators. Read the full section on eCFR

Quoted verbatim from the Electronic Code of Federal Regulations. Nothing here is a paraphrase, and nothing here is legal advice on a citation.

Times recorded104,00622% as often as 393.9, the most cited
How common27thof the 200 most cited codes, out of 2,372 that exist
Regulation393.53Parts and accessories

How often this comes up

This violation was recorded 104,006 times across the roadside inspections in the FMCSA file, making it the 27th most frequently cited code. Whether a given instance puts a vehicle or driver out of service is decided at the roadside by the inspector, not by the code itself, so the same violation can end a trip or simply be noted.

It sits under 49 CFR Part 393, which covers parts and accessories. To see it in context, look up a carrier and read its inspection history: the same code appearing repeatedly is a different signal from a single occurrence.

Look up a carrier's inspection record

Other parts and accessories violations

Counts are from the FMCSA Inspections and Violations file via data.transportation.gov. This describes how the violation is recorded, and is not legal advice on a citation.