What 393.45DLUV means in plain language
This code targets the physical condition of the brake tubing and hoses on your commercial motor vehicle. When an inspector finds that brake lines show signs of wear, chafing, crimping, or any other form of damage that compromises their integrity, that is what triggers a 393.45DLUV citation.
The concern is straightforward: brake tubing and hoses carry pressurized air or hydraulic fluid that activates your brakes. A hose that is rubbing against a frame rail, pinched by a mounting bracket, or visibly deteriorated can fail without warning. That is not a paperwork problem — it is a mechanical failure waiting to happen on the road.
Inspectors look at every section of brake tubing and hose they can access during a Level I or Level II inspection. They are checking for any sign that the line has been compromised — not just dramatic blowouts or complete separations, but the earlier-stage damage that most drivers do not notice during a quick walk-around.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.45DLUV has generated 14,478 all-time citations and ranks #176 out of 3,036 FMCSR codes by citation volume — placing it well inside the top 6% of all cited regulations nationally. That is not a rare or niche finding; inspectors across the country are flagging this regularly.
Enforcement has accelerated sharply in recent months. Over the last 12 months alone, our inspection records show 9,005 citations — meaning roughly 62% of all historical citations for this code were written in just the past year. The last 90 days account for 2,196 citations, a pace that suggests heightened inspector attention to brake system conditions.
Despite the volume, the out-of-service picture is more measured than you might expect. Our data shows that of 14,478 all-time citations, 425 resulted in an out-of-service order — a 2.9% OOS rate. To put that in perspective, the all-FMCSR average OOS rate across all codes is 31.4%. This code comes in more than ten times below that average, meaning inspectors are most often writing the citation and letting the driver proceed rather than parking the vehicle. That said, 425 OOS events on record proves it does happen, so the risk is not zero.
The code is also marked OOS-ineligible by default, which aligns with the low observed rate. Still, month-by-month data in our database shows OOS placements occurring consistently — 33 in October 2025, 31 in May 2025, and 27 in February 2026, among others — so the inspector on the scene retains discretion.
Who gets cited most
Looking at the last 180 days by state, Texas leads by a wide margin with 4,537 citations — dwarfing every other state in our records for this code. New Mexico comes in second at 131 citations, and Illinois third at 88 citations.
The OOS rate variation across those three states is worth noting. Texas sits at a 2.4% OOS rate on its 4,537 citations, while New Mexico shows 0.0% across its 131 citations. Illinois, however, runs at a 9.1% OOS rate on 88 citations — more than six percentage points above Texas and nearly four times the national observed rate for this code. If you are running through Illinois, inspectors there are placing vehicles out of service at a meaningfully higher clip than the national pattern suggests.
The heavy concentration in Texas and New Mexico strongly reflects cross-border commercial traffic. Our data shows fleets such as TRANSPORTES DE CARGA SAUL SALINAS SA DE CV (USDOT 557676) with 47 all-time citations and QUALITY TANK SA DE CV (USDOT 2864600) with 39 all-time citations appearing at the top of the carrier list — both operating in the cross-border corridor where brake system wear from high-mileage international routes is a documented enforcement pattern in our database.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.45DLUV sits in a very different tier than its peers when it comes to enforcement volume.
Consider 393.9(a), covering inoperable required lamps: our inspection records show 660,737 all-time citations — roughly 46 times the volume of 393.45DLUV — with a 15.4% OOS rate. Lighting violations are far more commonly cited, and they carry a substantially higher OOS risk than brake tubing hose condition citations.
Look at 396.3(a)(1), the general inspection, repair, and maintenance code: 236,919 citations in our database with a 45.3% OOS rate. That code's OOS rate is more than fifteen times higher than what we observe for 393.45DLUV. When inspectors find a broad maintenance failure under 396.3(a)(1), they are parking vehicles at a dramatically higher rate.
Then there is 393.47E, slack adjuster defective: 180,363 citations and a 0.0% OOS rate in our records. Like 393.45DLUV, this brake-adjacent code rarely results in an OOS placement on its own. The fact that 393.47E appears in 370 shared inspections with 393.45DLUV in the last 90 days alone tells you something important — brake system problems rarely travel alone.
How to avoid it
The co-occurring violation data in our database is the most practical prevention tool available. In the last 90 days, 393.45DLUV appeared on the same inspection report as 393.47E (slack adjuster defective) 370 times, and alongside 396.3A1BOS — the out-of-service brake defect code — 215 times. These patterns point to systemic brake system neglect rather than isolated hose wear. Here is what to do before you ever reach the scale:
- Trace every brake line from end to end during pre-trip. Run your hand or a flashlight along each section of tubing and hose, checking for contact points where the line rubs against the frame, axle, or suspension components. That contact point is where chafing begins.
- Check hoses at flex points specifically. The sections of hose that move with the suspension or steering — particularly near the front axle and glad hands — take the most abuse. Look for cracking, swelling, or any deformation.
- Inspect slack adjusters at the same time. Our data shows these two violations co-occur in 370 inspections over just 90 days. If your tubing is showing wear, your slack adjusters may also be past their service life. Check both together.
- Pay extra attention on Freightliner, Kenworth, and Peterbilt equipment. Our records show FRHT units account for 4,378 all-time citations under this code, KW units 2,122, and PTRB units 1,935. These are the most common platforms cited — not because they are inherently defective, but because they make up a large share of the CMV fleet. Know where the brake lines are routed on your specific model.
- Look for fuel system and lighting issues at the same time. 396.5B (fuel system leak) showed up in 390 shared inspections and 393.9 (inoperable required lamp) in 631 shared inspections in our last 90-day window. An inspector who finds one maintenance deficiency will keep looking. A thorough pre-trip that catches hose wear will often surface these other issues before they become citations.
- Document your inspection. If you find and report a brake hose issue before dispatch and it gets repaired, that paper trail protects you. If you find it at the roadside scale, it becomes a CSA severity weight 7 violation on your record.