What 393.45UV means in plain language
This regulation targets the physical condition of the brake tubing and hoses on your commercial motor vehicle. Inspectors are looking at whether those lines show signs of wear, chafing, crimping, or any other form of damage that compromises their integrity. It doesn't matter whether the brake system is still partially functional — if the lines themselves are visibly degraded, you're in violation.
Think of brake tubing and hoses as the arteries of your stopping power. They carry air or hydraulic pressure from the source to each brake assembly. When a hose is rubbed raw against a frame rail, kinked from an improper routing, or cracked from age and heat cycles, its ability to sustain that pressure under load becomes unreliable. That's exactly what the regulation is designed to catch before a failure happens on the road.
It's worth noting that 393.45UV is not the only brake-hose code inspectors use — our data shows 393.45B2UV co-occurring in 92 shared inspections during the last 90 days alone, meaning inspectors often find more than one hose-related defect on the same unit. If one line is cited, expect the rest of the system to receive close scrutiny.
What our enforcement data actually shows
Across the TruckCodex database, 393.45UV has generated 2,699 all-time citations, placing it at #470 out of 3,036 FMCSR codes by citation volume. That's a meaningful volume for a code most drivers have never heard of before a roadside stop.
The out-of-service picture deserves your full attention. Our inspection records show that 1,128 of 2,699 cited vehicles — 41.8% — were placed out of service on the spot. The all-FMCSR average OOS rate across our database is 31.4%, meaning 393.45UV runs more than 10 percentage points above that average. Even though this code is technically not OOS-eligible on its face, inspectors clearly have discretion to park vehicles when the hose condition is bad enough, and they are exercising it at an above-average rate.
Enforcement activity is not slowing down. Over the last 12 months, our database recorded 1,829 citations — that's roughly 68% of the entire all-time citation count accumulated in just one year. The last 90 days added another 372 citations. Monthly volume has been consistently high: October 2025 produced 192 citations, August 2025 produced 171, and no single recent month has dropped below 138 citations (aside from the partial April 2026 data). This is an actively enforced code right now.
Who gets cited most
Looking at the last 180 days of our inspection records, Texas dominates the citation map with 740 citations — by a wide margin. New Mexico is a distant second at 92 citations, followed by Illinois at 9 citations. If your lanes run through the southern border corridor, this code is a live threat at nearly every weigh station and mobile enforcement stop.
The OOS rate variation across those top states is material and worth paying attention to. In New Mexico, 47.8% of cited vehicles were placed out of service. Texas came in at 36.9%. Illinois sat at 33.3%. That nearly 11-percentage-point spread between New Mexico and Texas tells you that inspectors in New Mexico are parking a significantly higher share of vehicles they flag for this code — something to factor into your pre-trip diligence before crossing that state line.
Our data shows fleets such as TRANSPORTE INTERNACIONAL LOPEZ OCHOA SA DE C V (USDOT 1041907) with 21 all-time citations and AUTOTRANSPORTES ROMEDU SA DE CV (USDOT 1148259) with 18 all-time citations appear at the top of the citation table. The concentration of Mexican-domiciled carriers in the top-cited list aligns with the heavy Texas and New Mexico enforcement geography — border-crossing commercial traffic receives intensive inspection at ports of entry and nearby checkpoints.
On the equipment side, Freightliner (FRHT) leads all makes with 855 all-time citations, followed by Kenworth (KW) at 535 and International (INTL) at 239. Peterbilt (PTRB) adds another 237. If you're running any of these platforms, your brake lines are exactly what inspectors are trained to scrutinize.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.45UV sits in a different enforcement tier than most of its peers. Consider 393.9(a) — Inoperable Required Lamps — which has accumulated 660,737 citations in our database but carries only a 15.4% OOS rate. Brake tubing defects send vehicles out of service at 41.8%, more than double the rate of lamp violations, with a fraction of the overall citation volume.
Look at 396.3(a)(1) — the general Inspection/Repair/Maintenance code — which shows 236,919 citations and a 45.3% OOS rate. That's the closest peer in terms of OOS severity, and it frequently co-occurs with 393.45UV (67 shared inspections in the last 90 days). When inspectors write that general maintenance code alongside a brake hose defect, it signals a vehicle with a pattern of deferred upkeep, not just a single isolated issue.
Compare also to 393.47E — Slack Adjuster Defective — which has 180,363 citations but a 0.0% OOS rate in our database under that code. Brake hose defects are treated as substantially more serious at roadside than adjustment issues alone.
The CSA severity weight for 393.45UV is 7, which means this citation does real damage to your carrier's Safety Measurement System scores regardless of whether you were parked.
How to avoid it
The co-occurring violation data from our last 90 days points directly at what inspectors find when they dig into a vehicle that triggered a brake hose write-up. Use that pattern to build your pre-trip routine:
- Trace every brake hose and air line during pre-trip. Run your hand and your eyes along the full length of each hose from fitting to fitting. Feel for soft spots, bulges, or abrasion damage. Look for any point where a hose contacts metal — frame rails, cross-members, or other hoses — because that contact point is where chafing starts.
- Check slack adjusters while you're at the wheels. 393.47E co-occurred in 69 shared inspections in the last 90 days. If your brake hoses are deteriorating, your adjusters may be out of spec too. A quick stroke check takes 60 seconds per wheel.
- Look for fuel leaks at the same time. 396.5B (Fuel system leak) appeared in 59 shared inspections. Fuel contamination degrades rubber hose compounds rapidly. If you see a fuel seep anywhere near brake lines, treat it as an emergency, not a monitor-and-report situation.
- Inspect steering system components. 393.53B (Steering system components worn) was flagged in 61 shared inspections. A thorough under-vehicle walk catches both brake hose routing problems and steering wear in the same pass.
- Don't overlook the trailer. Utility (UTIL) trailers account for 204 all-time citations. Glad-hand connections and trailer service lines take abuse at every hook-up. Add them explicitly to your coupling inspection checklist.
- Address any deferred maintenance before dispatch. 396.3A1 (Inspection, repair, and maintenance) co-occurred in 67 shared inspections. That code shows up when a vehicle has a documented history of skipped or incomplete maintenance. One open repair order can invite a full inspection that surfaces a brake hose violation you didn't know existed.