393.45 Violation: What It Means and How to Fix It
Data through September 24, 2026 · Last updated October 28, 2026 · By Chad Griffith, founder
Quick Answer
393.45 (Brake tubing and hoses; hose assemblies and end fittings) was cited 78,624 times in roadside inspections of interstate for-hire carriers with 5 to 50 trucks from September 25, 2024 to September 24, 2026, and 26.8% of those citations put the driver or vehicle out of service. The most common version is 393.45D-B: Air Brake - Audible air leak at a proper connection.
78,624
Citations on carriers with 5 to 50 trucks
26.8%
Out of service
374,678
All carriers, same period
What the rule says
Brake hoses and tubing must be secured against chafing and kinking, free of damage, and must not leak at connections (49 CFR 393.45).
When it puts you out of service
An audible leak at a connection is rarely out of service; a hose damaged through the outer reinforcement ply is out of service 93% of the time in this data.
The codes on the inspection report
| Code | What the officer wrote | Severity weight | Citations, 5 to 50 trucks | Out of service |
|---|---|---|---|---|
| 393.45D-B | “Air Brake - Audible air leak at a proper connection” | 4 | 20,020 | 0.4% |
| 393.45B2-B-AIR | “Air Brake - Hose/tubing damaged or not secured” | 4 | 19,494 | 2.3% |
| 393.45B2-BHTD | “Air Brake - Hose/tubing damage into the outer reinforcement ply.” | 4 | 10,786 | 93.2% |
| 393.45B2UV | “Brake Hose or Tubing Chafing and/or Kinking Under Vehicle” | 4 | 5,494 | 14.8% |
| 393.45D-BAAL | “Air Brake - Audible air leak at other than a proper connection” | 4 | 4,660 | 84.1% |
| 393.45B2PC | “Brake Hose or Tubing Chafing and/or Kinking - Connection to Power Unit” | 4 | 3,089 | 30.7% |
| 393.45DLUV | “Brake Connections with Leaks Under Vehicle” | 4 | 2,588 | 3.4% |
| 393.45DLPC | “Brake Connections with Leaks - Connection to Power Unit” | 4 | 2,545 | 3.1% |
| 393.45 | “Brake tubing and hose adequacy” | 4 | 1,389 | 75.4% |
| 393.45B2 | “Brake hose or tubing chafing and/or kinking” | 4 | 1,283 | 19.5% |
| 393.45B2-B | “Air Brake - Hose/tubing damaged or not secured” | 4 | 1,087 | 9.4% |
| 393.45D | “Brake connections with leaks or constrictions” | 4 | 861 | 26.1% |
How it scores (violation points)
How it scores: in FMCSA's Safety Measurement System each violation counts its severity weight, plus 2 if it put the driver or vehicle out of service, times 3 in its first 6 months, 2 from 6 to 12 months, and 1 from 12 to 24 months. FMCSA has approved a simpler scale that is not live yet.
How to fix it
- Replace the damaged hose or fitting before the unit runs; do not tape or splice an air line.
- Re-secure loose lines with clamps or chafe guards and note the repair on the inspection report.
- Listen for leaks on every unit at the next yard check.
Stop it happening again
- Add hose chafe points and glad-hand seals to the preventive maintenance checklist.
Challenging it in DataQs
Use DataQs (dataqs.fmcsa.dot.gov) only when the report is wrong: the wrong carrier or vehicle, a violation that did not happen, or a citation a court dismissed without a fine or found you not guilty of, which removes it from the Safety Measurement System; a conviction of a different charge lowers its weight to 1 (FMCSA adjudicated citations policy). Fixing the defect afterward is not a reason to remove it; keep the repair record instead.
FileFlo reads your public FMCSA record, lists every violation with the rule behind it, and keeps the driver and vehicle records that stop repeats.
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About these numbers
Counts are violations cited in roadside inspections used in FMCSA's Safety Measurement System from September 25, 2024 to September 24, 2026 (dataset 8mt8-2mdr on data.transportation.gov, October 2026 run). Carriers with 5 to 50 trucks means 66,936 active interstate for-hire carriers with 5 to 50 power units and more trucks than buses, based in the 50 states or DC, from FMCSA's census file. This is FileFlo's reading of public FMCSA data, not an FMCSA rating. Severity weights are the current SMS weights.