What 393.45DCUV means in plain language
Brake tubing and hoses are the conduits that carry pressurized brake fluid from your truck's brake valve to each wheel cylinder. When these lines are worn, chafed, crimped, or otherwise damaged, they can leak or rupture—and that means your brakes stop working as designed.
The regulation requires that all brake tubing and hoses remain intact and free from defects that compromise their function. If an inspector finds tubing that's frayed against a sharp edge, hoses with visible cracks, crimped sections that restrict flow, or any other damage, you'll be cited under 393.45DCUV.
This is a maintenance issue, not a driver behavior violation. It depends entirely on the condition of your vehicle when you pull up to the scale.
What our enforcement data actually shows
Across our 13 million+ inspection records, we've issued 1,504 citations for 393.45DCUV all-time, with 824 citations in the last 12 months and 217 in the last 90 days. This code ranks #604 out of 3,036 FMCSR codes by citation volume—relatively uncommon, but not rare.
The out-of-service rate for 393.45DCUV is 7.0% (105 vehicles placed OOS out of 1,504 total citations). Compare that to the all-FMCSR average of 31.4%: brake tubing and hose violations result in OOS placement far less often than the typical vehicle maintenance citation. Most inspectors will issue a warning or citation but allow you to continue if the damage isn't critical; however, roughly one in fourteen inspections still results in a truck being pulled from service.
The monthly trend shows consistent enforcement. Over the past 12 months, citations ranged from a low of 22 in April 2025 to a high of 101 in February 2026, indicating steady pressure on this violation year-round.
Who gets cited most
Texas dominates the citation count by a wide margin. Our inspection records show 416 citations in Texas over the last 180 days, with 13 resulting in out-of-service orders (3.1% OOS rate). Illinois follows with 7 citations and no OOS placements, while North Carolina and New Mexico each account for 2 citations with zero OOS outcomes.
The variation in OOS rates across states is material: Texas's 3.1% rate is significantly lower than the national 7.0% average for this code, suggesting that inspectors in other regions may enforce more aggressively when tubing or hoses are found defective.
When we look at carrier-level data, our records show fleets such as AUTOTRANSPORTE CA-RI SA DE CV with 23 citations, MP EXPRESS LOGS SA DE CV with 15 citations, and AUTOLINEAS PERZA SA DE CV with 14 citations. These numbers reflect raw citation volume across their fleets; they do not imply systematic neglect, but rather that larger or geographically dispersed operations encounter this violation more frequently.
How severe is this compared to similar codes
Brake system maintenance violations fall within the broader vehicle maintenance category. When we compare 393.45DCUV to peer codes:
393.9 (Inoperable Required Lamp) has been cited 180,097 times with a 6.9% OOS rate—nearly identical in severity and enforcement frequency as 393.45DCUV, though lamp issues vastly outnumber brake tubing violations.
393.47E (Slack adjuster defective) has been cited 180,363 times but with a 0.0% OOS rate, meaning inspectors almost never pull trucks out of service for slack adjuster problems, even though the defect is equally safety-critical to brake function.
396.3(a)(1) (Inspection/repair/maintenance—general) is much more broadly cited at 236,919 times, but with a 45.3% OOS rate, indicating that general maintenance violations are enforced far more stringently than specific brake tubing defects.
In other words, 393.45DCUV sits in a middle ground: not as frequently cited as lighting or general maintenance, but carrying a meaningful—though below-average—risk of OOS placement.
How to avoid it
Break system maintenance doesn't happen at roadside; it happens during your pre-trip inspection and regular maintenance cycles. Use these actions to stay ahead of 393.45DCUV:
-
Walk your entire brake system before every trip. Get down and trace every foot of tubing and hose from the brake valve under the tractor, along the frame rails, and out to each wheel. Look for chafing against sharp edges, cracks, bulges, or signs of leaking brake fluid. Our data shows 393.47E (slack adjuster defect) co-occurs in 35 of the last 90 days' 393.45DCUV inspections, meaning brake system neglect clusters together—if one component is failing, others often are too.
-
Fix chafing immediately. If you see tubing or hose rubbing against a frame member, weld guard, or sharp corner, wrap it or reroute it before you move the truck. This is a five-minute fix at the lot and a citation at the scale.
-
Replace hoses on schedule. Brake hoses degrade over time from heat, UV, and pressure cycling. Don't wait for visible cracks. Follow your manufacturer's service intervals and your fleet's maintenance program.
-
Keep your truck clean during inspections. Dirt, mud, and grease can obscure tubing damage. A clean undercarriage means inspectors can see what they're looking at, and you'll have a clearer picture too.
-
Know your vehicle make's weak points. Our data shows Freightliner trucks (465 citations), Kenworth (243 citations), and Peterbilt (138 citations) are most frequently cited for 393.45DCUV. If you drive one of these, brake tubing routing and durability are known friction points in the field—pay extra attention during pre-trip.
The 7.0% OOS rate means you're unlikely to be stranded, but a citation still hits your CSA record with a severity weight of 7 and feeds into your carrier's safety metrics. Prevention is faster and cheaper than dealing with the aftermath.