What 393.45PC means in plain language
This citation means an inspector found brake tubing or hoses on your commercial motor vehicle in a condition that makes them unfit for service. The regulation covers physical deterioration in several forms — tubing or hoses that show wear from rubbing against other components, chafing from contact with frame edges or brackets, crimping that restricts brake fluid or air flow, or any other form of damage that compromises the integrity of the brake line.
The core idea is simple: the brake system depends on tubing and hoses that can handle full operating pressure without failure. When those lines are compromised, the entire braking system becomes unreliable. Inspectors are trained to look for soft spots, abraded outer jackets, kinks, and areas where a hose has been pinched by a clamp or trapped against a moving part.
This is not a paperwork violation. It is a condition on the vehicle itself, and that distinction matters when it comes to how inspectors handle it at the roadside stop.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.45PC has generated 2,957 all-time citations, placing it at rank #443 out of 3,036 FMCSR codes by total citation volume. That puts it solidly in the top 15% of all codes by enforcement frequency — this is not an obscure technicality that inspectors rarely use.
Enforcement has been running hot recently. Our inspection records show 1,809 citations in the last 12 months and 346 in just the last 90 days, which signals sustained, active enforcement rather than a one-time surge.
The out-of-service picture here deserves close attention. Although 393.45PC is not OOS-eligible by designation, our database shows that 994 of 2,957 all-time citations still resulted in a vehicle being placed out of service — a 33.6% OOS rate. That is above the all-FMCSR average of 31.4%. The reason: when an inspector finds damaged brake tubing, there are almost always other defects present on the same vehicle, and one of those companion violations may carry an OOS threshold. Getting cited for 393.45PC dramatically increases your odds of going OOS on something else found during the same inspection.
Looking at the monthly trend, citations stayed consistently elevated throughout the past year. August 2025 was the peak month with 187 citations and 64 OOS placements. Even in lighter months like February 2026, 117 citations and 38 OOS placements were recorded. There is no slow season for this enforcement.
Who gets cited most
Texas leads all states in 393.45PC enforcement over the last 180 days with 645 citations and a 29.5% OOS rate. New Mexico is second with 162 citations — but its OOS rate of 49.4% is nearly 20 percentage points higher than Texas. That gap is material. If you are crossing into New Mexico, the same violation that might result in a citation-and-go in Texas is far more likely to result in a parking order there. Illinois recorded 9 citations at a 33.3% OOS rate over the same period.
The concentration in Texas and New Mexico reflects the heavy international commercial traffic crossing at southern border ports of entry. Our data shows fleets such as AUTOTRANSPORTES ROMEDU SA DE CV (USDOT 1148259) with 34 all-time citations and TRANSPORTE INTERNACIONAL LOPEZ OCHOA SA DE C V (USDOT 1041907) with 12 citations appearing at the top of the carrier list — consistent with the geographic pattern of enforcement along the southern border corridor.
On the vehicle side, Freightliner (FRHT) leads all makes with 1,040 citations, followed by Kenworth (KW) at 458 and Peterbilt (PTRB) at 361. Utility trailers (UTIL) account for 354 citations, a reminder that brake line condition on trailers gets scrutinized just as closely as on the power unit.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.45PC sits in a specific enforcement tier. Compare it to three peer codes from our database:
393.9(a) — Inoperable required lamps has been cited 660,737 times — more than 223 times as often as 393.45PC — but carries only a 15.4% OOS rate. It is one of the most common findings inspectors write up, but it pulls vehicles far less often. Brake tubing violations are rarer but hit harder.
396.3(a)(1) — Inspection/repair/maintenance (general) has 236,919 citations in our records and a 45.3% OOS rate. That higher OOS rate reflects that inspectors writing this code have typically found systemic maintenance failures, not isolated defects. If 393.45PC and 396.3(a)(1) both appear on your inspection report, expect serious consequences.
393.78 — Windshield condition defective shows 157,894 citations at a 0.3% OOS rate — high volume, almost no OOS impact. That contrast underscores why brake-related findings are in a different risk class than visibility or lighting write-ups.
The CSA severity weight for 393.45PC is 7 out of a possible 10. That weight flows directly into your Safety Measurement System score and stays on the record for two years at full weight, then a third year at reduced weight.
How to avoid it
Our inspection records show 393.45PC appearing alongside other violations in patterns that point to specific pre-trip actions you can take every single time you roll.
- Walk the entire brake line on both tractor and trailer. In the last 90 days, 393.45B2UV (a related brake tubing code) co-occurred on 40 shared inspections, and 393.47E (slack adjuster defective) appeared on 34. Brake system problems cluster. If you find one issue, keep looking — there are likely more.
- Check hoses at flex points and mounting brackets specifically. Chafing happens where tubing contacts metal. Run your hand along lines near frame rails, air tank brackets, and any location where the hose moves with suspension travel. Feel for soft spots, cuts, and abraded areas that the eye might miss.
- Inspect trailer brake lines at the glad hand connection and along the entire length to the rear axle. Utility trailers account for 354 all-time citations under this code. Trailer lines are exposed, often older, and frequently overlooked during quick pre-trips.
- After any maintenance that involved brake work, verify line routing before departure. Crimps are often introduced during repairs when a hose is reinstalled incorrectly or pinched under a bracket.
- Use co-occurring violations as a checklist trigger. Our data shows 393.9 (required lamp inoperable) on 79 shared inspections and 396.5B (fuel system leak) on 40. If you find a lamp out or smell fuel, treat the entire vehicle as inspection-ready suspect and do a full systems walk before leaving the yard.
- Know your risk by state. If your lane runs through New Mexico, the 49.4% OOS rate in our data means borderline brake line condition that might pass elsewhere is likely to park you. Fix it before you cross.