FMCSR 393.45B2: Brake Tubing/Hoses Inadequate — Driver Q&A

Not automatically — but it happens nearly 1 in 5 times. Although 393.45B2 is not OOS-eligible on its face, our inspection records show that 926 of 4,676 all-time citations still resulted in an out-of-service order, producing a 19.8% OOS rate. That likely reflects inspectors bundling this finding with a more severe brake defect on the same inspection. For comparison, the all-FMCSR average OOS rate across all codes is 31.4%, so this code runs below average — but "below average" still means nearly one in five cited trucks got parked. Don't assume damaged tubing or hose is a free pass through the scale.

393.45B2 carries a severity weight of 7 on the CSA scoring scale. That base score is then multiplied depending on how recently the inspection occurred: violations within 6 months of the current review period carry the highest time-weight multiplier, violations between 6–12 months carry a lower one, and those older than 12 months carry the lowest. The 7-point severity weight puts this code in a meaningful tier — it's not the worst brake-related score possible, but it directly feeds your Vehicle Maintenance BASIC and can push a fleet toward intervention thresholds if citations accumulate. Across our database, 2,515 citations were issued in just the last 12 months, so inspectors are actively writing this violation.

Get the brake tubing and hoses inspected and repaired by a qualified mechanic before your next dispatch. Here's what the data tells you to do right away:

1. Fix the cited defect first. Worn, chafed, crimped, or damaged brake lines are the core finding — document the repair with a dated work order.
2. Do a full brake system walk-around. In our last 90 days of inspections, 393.47E (slack adjuster defective) appeared on 29 of the same inspections as this code. Inspectors who find one brake issue look for others.
3. Check your lights and emergency equipment. 393.9 (inoperable required lamp) co-occurred on 49 inspections and 393.95A (fire extinguisher) on 37 — these are frequent companion violations.
4. Confirm your periodic inspection paperwork. 396.17C (no proof of periodic inspection) appeared on 40 of the same inspections. Have it in the cab.

It's a mid-tier violation by volume but carries a real OOS risk profile. At 4,676 all-time citations, 393.45B2 ranks #354 out of 3,036 FMCSR codes — it's cited regularly but not among the highest-volume codes. Its 19.8% OOS rate sits below the all-FMCSR average of 31.4%, which might suggest lower severity — but look at what peers produce: 396.3(a)(1) (general inspection/repair) generates a 45.3% OOS rate across 236,919 citations, and 393.47E (slack adjuster defective) has 180,363 citations. In context, 393.45B2 is a focused, equipment-specific finding that a thorough pre-trip inspection should catch every time. The 7-point CSA severity weight also means it scores harder than a lighting defect.

Yes, you can submit a DataQs request for review (RDR) if the citation is factually incorrect. Because 393.45B2 is an equipment-condition finding — not a missing-document violation — a successful challenge typically requires evidence that the brake tubing and hoses were actually in acceptable condition at the time of inspection: post-inspection repair records with the technician's assessment, photos taken at the scene, or a second inspection report that contradicts the original finding. DataQs challenges on equipment-condition citations succeed less often than documentation disputes because the inspector's on-scene findings carry significant weight. Still, if the violation was written in error or on the wrong vehicle/unit, the RDR process exists specifically to correct the record. Submit through the FMCSA DataQs portal and track the case number.

Iowa leads by a wide margin, followed by New Mexico and Illinois. Looking at the last 180 days in our inspection records: Iowa issued 643 citations (with a 16.8% OOS rate), New Mexico issued 101 citations (32.7% OOS rate), and Illinois issued 66 citations (34.8% OOS rate). If your lanes run through Iowa in particular, the exposure is significant — 643 citations from one state alone dwarfs every other state in the dataset. Note that New Mexico and Illinois both have OOS rates nearly double Iowa's, meaning that when those states cite this violation, they're more likely to park the truck.

Don't wait. The 90-day citation volume of 335 inspections shows inspectors are actively writing this finding right now, and the monthly trend peaked at 366 citations in a single month (2025-05) over the last year. More directly: 19.8% of all-time citations resulted in an out-of-service order despite this code not being formally OOS-eligible — that means inspectors regularly find the condition severe enough to park the truck under a related provision. Damaged brake tubing or hoses that are worn, chafed, or crimped affect brake pressure and response. Delaying repair until a scheduled PM interval is a real OOS and safety risk, especially since co-occurring violations like 393.47E (slack adjuster, 29 shared inspections in 90 days) suggest inspectors are doing thorough brake inspections when they find this code.

It follows both — the carrier takes the primary hit, but the driver's record is also affected. In FMCSA's CSA system, equipment violations like 393.45B2 are attributed to the carrier's Vehicle Maintenance BASIC, which is where fleet intervention thresholds are calculated. The driver's own inspection history is also recorded and can affect their safety profile and hiring decisions. The data backs up why carriers should care: our records show large fleets like SWIFT TRANSPORTATION CO OF ARIZONA LLC (23 citations, USDOT 54283), NEW PRIME INC (21 citations, USDOT 3706), and EVANS DELIVERY COMPANY INC (20 citations, USDOT 38111) among the most-cited carriers all-time — accumulated citations across a fleet move the BASIC percentile, not just any single driver's score.