What 396.5B means in plain language
FMCSR 396.5B targets a straightforward but serious mechanical condition: operating a commercial motor vehicle when any part of its fuel system is leaking. That covers everything from a dripping fuel line to a weeping tank seal or a loose fitting anywhere along the path fuel travels from the tank to the engine.
The rule doesn't require the leak to be large or actively spraying to trigger a citation. Inspectors are trained to check for staining, wet spots, drips, and fuel odor during a walkaround. If they find evidence that fuel is escaping the system anywhere it shouldn't be, you can expect a 396.5B on your inspection report.
The practical concern is obvious: an uncontrolled fuel leak near hot engine components or electrical wiring is a fire hazard. It also means fuel is depositing on the road surface, creating a hazard for vehicles behind you. This is why inspectors flag it even when the leak appears minor.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, 396.5B has generated 42,528 all-time citations, placing it at #73 out of 3,036 FMCSR codes by citation volume. That is a high-frequency violation. Over just the last 12 months, our inspection records show 26,630 citations — meaning roughly 63% of all historical citations for this code occurred in the past year alone. In the last 90 days, 6,683 citations were issued nationally.
Despite that volume, the out-of-service picture is notably mild. Of the 42,528 all-time citations in our database, only 100 resulted in an OOS order — an OOS rate of just 0.2%. To put that in context, the all-FMCSR average OOS rate across every code in our database is 31.4%. A 0.2% rate means inspectors are citing this condition frequently but placing almost no one out of service for it. In practical terms, you almost certainly kept rolling after receiving this citation — but the violation is still on your record and still carries a CSA Severity Weight of 7.
Looking at the monthly trend in our data, citations have been climbing steadily. From 2,129 in May 2025, enforcement activity has risen to 2,791 in March 2026, with a peak of 2,978 in February 2026. That upward trajectory suggests inspectors are paying closer attention to fuel system condition than they were a year ago.
Who gets cited most
Our inspection records show a sharp geographic concentration for this violation. Over the last 180 days, Texas leads all states by a wide margin with 13,433 citations, followed distantly by New Mexico at 226 citations and Illinois at 122 citations.
The OOS rate variation across those three states is worth noting. Texas and New Mexico both show 0.0% OOS rates, meaning virtually no drivers were placed out of service despite thousands of citations. Illinois, however, shows a 13.1% OOS rate on its 122 citations — more than 13 percentage points higher than Texas. That kind of divergence suggests that inspection context matters: if you're rolling through Illinois with a visible fuel leak, the likelihood of an OOS order is meaningfully higher. Iowa also shows a 4.6% OOS rate on 109 citations, and North Carolina a 7.4% rate on 54 citations, reinforcing that enforcement outcomes are not uniform nationwide.
On the carrier side, our data shows fleets such as TRANSPORTES AGUILA DE CIUDAD JUAREZ SA DE CV (USDOT 555365) with 202 all-time citations and OPERADORA DE TRANSPORTE INTERNACIONAL SA DE CV (USDOT 683428) with 185 citations appearing at the top of the volume list. The concentration of high-citation carriers operating cross-border routes is consistent with the heavy Texas enforcement footprint in our records.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 396.5B sits in an interesting position relative to its peers. Consider 396.3(a)(1) — Inspection/repair/maintenance - general, which has 236,919 all-time citations in our database and carries a 45.3% OOS rate. That code sends nearly half of cited drivers off the road immediately. By comparison, 396.5B's 0.2% OOS rate means it almost never results in an immediate shutdown — but it still earns a CSA Severity Weight of 7.
393.9(a) — Inoperable required lamps has accumulated 660,737 citations with a 15.4% OOS rate, making it far more common and more likely to sideline a driver than a fuel system leak citation. Meanwhile, 393.78 — Windshield condition defective sits closer to 396.5B's profile with 157,894 citations and a 0.3% OOS rate — high volume, low OOS, but real CSA point exposure.
The takeaway: 396.5B won't likely park your truck, but its CSA Severity Weight of 7 means it accumulates points in your SMS score that affect carrier safety ratings and can trigger interventions over time.
How to avoid it
The co-occurring violation pattern in our data tells a clear story: drivers cited for 396.5B are frequently cited for several other conditions during the same inspection. That means the fuel leak rarely exists in isolation — it's part of a broader deferred-maintenance pattern. Here's what to check before every trip:
- Walk the entire fuel system during your pre-trip. Start at the tank and trace the fuel lines forward to the engine. Look for wet spots, fuel staining on frame rails, drips on the ground under the tank, and any smell of diesel. Pay particular attention to fittings, clamps, and the fuel filter housing.
- Check brake components while you're underneath. Our data shows 393.45B2UV (brake tubing/hoses inadequate) and 393.47E (slack adjuster defective) are among the most common co-occurring codes. If you're already under the truck checking the fuel tank, inspect brake lines and slack adjusters at the same time.
- Inspect required lamps. Code 393.9 (Inoperable Required Lamp) appeared in 2,256 shared inspections with 396.5B in just the last 90 days. A quick walkaround lamp check takes two minutes.
- Check exhaust routing. Code 393.83G (exhaust discharging forward of or directly below the cab) appeared in 1,114 shared inspections. A displaced or damaged exhaust stack near a fuel line is a compounding hazard — look for both on the same pass.
- Know your vehicle make's weak points. Freightliner (FRHT) accounts for 14,399 all-time 396.5B citations in our database, followed by Kenworth (KW) at 6,013 and Peterbilt (PTRB) at 4,611. If you drive one of these platforms, fuel line condition should be a standing pre-trip focus, not an afterthought.
- Don't defer the repair. Because 396.5B almost never results in an OOS order, some drivers treat it as a low-urgency item. That's a mistake. A fuel leak that earns you a citation today is a fire risk tonight, and the CSA points accumulate regardless of whether you were parked.