§393.65 sets fuel-system construction and condition requirements. The fuel system must be substantial enough to resist fatigue and impact, mounted to prevent damage from heat or ignition sources, equipped with a filler-cap of compatible thread and seal, and operate without leaks under all conditions of vehicle operation. Visible leaks — even drips — are OOS.
OOS criteria
Any visible fuel leak from any portion of the fuel system places the vehicle OOS under the NAS Out-of-Service Criteria. The vehicle cannot be driven from the inspection site until the leak is repaired. Repair must be certified before the vehicle returns to service.
Severity
Severity weight 3 in the Vehicle Maintenance BASIC. Beyond the weight, fuel-system findings are the most common cause of roadside-inspection-induced delivery delays — OOS at roadside means the vehicle waits for a repair before it moves.
How to prevent it
- DVIR pre-trip inspection includes a walk-around with the engine running, checking for visible fuel weep at fittings.
- Filler-cap inspection at every fueling — missing or damaged caps fail §393.65 in their own right.
- Track tank-strap condition; tanks dropping due to corroded straps are a common precursor to leak findings.
How Roadworthy HQ helps
A fuel-system citation shows up in Roadworthy HQ as part of the inspection it came from, not as a record of its own: the app does not store individual violation codes. Log the roadside inspection on the vehicle's Inspections tab: date, state, level, driver, the number of violations, and whether it was out-of-service. For an out-of-service inspection the 15-day §396.9(d)(3) repair-certification countdown stays on that tab until you enter the certification date. The rule's 15 days cover every violation on the report, not only out-of-service ones, so for a non-OOS inspection that date is yours to track. The repair itself goes in the vehicle's maintenance log: date, type, what was done, who did it, and cost. DVIRs are logged per vehicle with the defect described in your own words, and a defect marked safety-affecting that is logged without a repair certification sends a critical alert.