FMCSR 393.45D: Brake Tubing/Hose Violations Explained

It can, but it doesn't always. Across 3,113 all-time citations in our inspection records, 393.45D carries a 21.7% out-of-service rate — meaning roughly 1 in 5 inspections with this violation resulted in the truck being parked. That's actually below the all-FMCSR average OOS rate of 31.4%, so inspectors don't pull every truck for this code. However, 393.45D is OOS-eligible, so the condition of the hose or tubing at the time of inspection is the deciding factor. A badly chafed or crimped brake line near failure is a different conversation than minor surface wear. Don't assume low odds mean no risk.

393.45D carries a CSA severity weight of 7. That places it in the upper-middle tier of the severity scale. The actual points that hit your SMS record are multiplied based on how recently the violation occurred: inspections in the last 6 months receive the highest time-weight multiplier, inspections 7–12 months back receive a lower one, and inspections older than 12 months receive the lowest. Because 393.45D sits in the Vehicle Maintenance BASIC, the points affect the carrier's Vehicle Maintenance BASIC score — but the violation also links to the driver's record. The closer the citation date is to today, the harder it hits your score.

Get the brake tubing or hose inspected and repaired by a qualified mechanic before your next dispatch. Here's what the co-occurrence pattern from our database tells you to prioritize alongside that repair:

1. Check all required lamps — 393.9 (Inoperable Required Lamp) appeared in 40 shared inspections in the last 90 days alongside 393.45D.
2. Verify your fire extinguisher — 393.95A showed up in 32 shared inspections.
3. Pull your maintenance records — 396.3A1 and 396.17C (No proof of periodic inspection) each appeared in 30 shared inspections, suggesting paperwork gaps often accompany this finding.
4. Inspect slack adjusters — 393.47E co-occurred 27 times.

Fix the brake tubing first; then work through this list before your next roadside stop.

It's moderately serious — not the worst in its category, but far from trivial. With a 21.7% OOS rate, 393.45D sits below the all-FMCSR average of 31.4%, which sounds favorable. But compare it to peer codes: 396.3(a)(1) general inspection/maintenance carries a 45.3% OOS rate across 236,919 citations, and even 393.47E (slack adjuster defective) has accumulated 180,363 citations. By citation volume, 393.45D ranks #431 out of 3,036 FMCSR codes — active enough to be on inspectors' radar. The CSA severity weight of 7 also means this isn't a paperwork technicality; it reflects a real safety concern around brake system integrity.

Yes, you can file a DataQ challenge, and equipment-based findings like 393.45D are contestable if the record is factually incorrect. The FMCSA DataQs system (Request for Data Review, or RDR) lets drivers and carriers dispute inspection data that is inaccurate, incomplete, or not in compliance with federal or state regulations. Because 393.45D is an equipment condition finding — not a documentation violation — a successful challenge typically requires evidence like repair invoices, inspection photos, or a certified mechanic's assessment showing the cited condition either didn't exist or was misidentified. Submit through the FMCSA DataQs portal, reference the inspection report number, and attach supporting documentation. Most decisions come back within 45 days.

Iowa, New Mexico, and Illinois account for the highest 393.45D citation volumes over the last 180 days. Our inspection records show Iowa leading with 184 citations, followed closely by New Mexico at 173 and Illinois at 131. North Carolina logged 86 citations in the same window. One important nuance: New Mexico's OOS rate for this code is 34.1% and North Carolina's is 44.2%, both well above Iowa's 13.6% and Illinois's 14.5%. That means a New Mexico or North Carolina inspector citing 393.45D is significantly more likely to park the truck than one in Iowa or Illinois. If your routes cross those states, the stakes at the roadside are meaningfully higher.

Don't wait. Our database recorded 248 citations in just the last 90 days, and 393.45D has a 21.7% OOS rate — so more than 1 in 5 trucks cited for this are being parked on the spot. Monthly data from the last year shows enforcement is consistent, ranging from 62 to 197 citations per month with no sign of dropping off. Brake tubing and hoses are safety-critical components; a worn or crimped hose can degrade braking performance and escalate to a full brake system failure. Waiting until a scheduled PM introduces both safety risk and the risk of a second citation before the defect is corrected. Repair it now.

Both. Under FMCSA's CSA methodology, a violation cited during a roadside inspection attaches to the carrier's BASIC score and to the driver's individual Inspection Selection System (ISS) profile. For 393.45D, the points land in the Vehicle Maintenance BASIC for the carrier. The driver's record reflects the inspection outcome and can influence how screening systems prioritize that driver for future inspections. This matters practically: if a driver moves to a new carrier, their inspection history travels with them. For fleet managers, it means a vehicle defect citation isn't just the truck's problem — it follows the driver too, and repeated findings across your fleet compound the carrier's Vehicle Maintenance BASIC score.