Prevention FAQ — FMCSR 393.65B (Flat/Leaking Tires)

Inspectors cite this violation when a tire is completely flat or has an audible air leak during the pre-trip or roadside walk-around. Our inspection records show 17 citations in the last 12 months, with Texas accounting for 16 of those across the last 180 days. Inspectors use visual confirmation (deflated sidewall) and listen for hissing or air escape—both require no special equipment. The violation is cited whether the vehicle is moving or stopped, and regardless of tire age or tread depth. A tire losing pressure audibly means it will fail within hours; inspectors do not wait for complete deflation to cite.

Your pre-trip checklist must include: (1) Visual walk-around of all tires—check for cuts, punctures, bubbles, and obvious deflation by comparing tire sidewall bulge across all wheels; (2) Tire pressure verification using a calibrated gauge on at least the drive axles, confirming PSI meets placard requirements; (3) Listening for air leaks near valve stems and sidewalls when the engine is off; (4) Checking spare tires if carried. Document the date, time, odometer reading, and tire condition in writing before departure. Across our data, flat and leaking tires co-occur with inspection/repair maintenance defects in 4 shared inspections in the last 90 days—suggesting vehicles with chronic maintenance backlogs are at risk.

Drivers must carry a completed, dated pre-trip inspection report showing tire PSI and condition for each day of operation. Fleets must retain: (1) Pre-trip inspection records for minimum 1 year; (2) Tire maintenance logs (repairs, rotations, replacements) with date, technician name, and action taken; (3) Tire pressure baseline settings per axle and vehicle type; (4) Proof of calibrated tire gauge testing/certification. Our data shows no citations resulted in out-of-service orders, but strong documentation protects the carrier during post-citation review and supports a DataQs challenge if the inspection was erroneous. Keep records accessible for audits.

Our 90-day co-occurrence data reveals three systemic patterns: (1) Inspection/maintenance backlog — 4 shared inspections with code 396.3A1 (inspection/repair/maintenance defects) suggests vehicles are not receiving timely pre-use checks. (2) Windshield and lighting neglect — 3 inspections paired with 393.78 (defective windshield) indicates a broader inattention to vehicle walk-arounds and condition verification. (3) Brake and coupling issues — 1 shared inspection each with codes 393.45B2UV and 393.55D flags suggest fleets deferring multiple mechanical repairs simultaneously, including tire maintenance. Root cause: inadequate pre-trip discipline and deferred maintenance schedules.

After any tire repair or replacement: (1) Use a calibrated tire gauge to verify PSI matches the vehicle's manufacturer placard for each axle; record the reading on a repair ticket. (2) Physically inspect the repair site and surrounding sidewall for cracks, bulges, or seepage under shop lighting. (3) Perform a manual leak test by applying soapy water to valve stems and repair areas—bubbles indicate ongoing air loss. (4) Road-test the vehicle at low speed (10–15 mph) and listen for hissing. (5) Re-check pressure 24 hours post-repair; a drop >2 PSI signals incomplete repair. (6) Document all findings with date, technician initials, and approval before the vehicle is assigned to a driver.

Conduct a structured post-citation review within 48 hours: (1) Driver interview — Was the tire flat or leaking prior to departure? Did the driver conduct a pre-trip check? (2) Vehicle inspection — Inspect the cited tire and all others; check pressure, valve stem condition, and repair history. (3) Maintenance records review — Pull the vehicle's last three tire inspections and rotations; identify gaps. (4) Root cause determination — Determine if the issue was driver error (skipped pre-trip), deferred maintenance, or a defective tire that should have been replaced. (5) Corrective action — Retraining, maintenance scheduling adjustment, or equipment replacement. Document the review and action taken for your safety file.

Yes. This violation carries a severity weight of 8 in the Vehicle Maintenance BASIC and is ranked #1881 of 3,036 FMCSR codes—meaning it affects your safety profile but is not among the highest-volume violations. The 0.0% out-of-service rate (compared to the all-FMCSR average of 31.4%) indicates inspectors view this as a correctable defect rather than an acute safety failure. However, CSA scoring is cumulative; one citation alone may have minimal impact, but repeated citations or a pattern across your fleet signals systemic maintenance weakness to auditors and insurers.

Prioritize these training modules: (1) Visual inspection technique — Teach drivers to compare tire sidewall bulge across all wheels and recognize loss of pressure visually. (2) Listening for leaks — Demonstrate audible leak detection in a quiet bay; play audio samples of valve stem and sidewall hissing. (3) PSI verification — Train on proper gauge use, placard location, and acceptable pressure ranges per axle. (4) Consequences of operation — Explain that a flat tire can cause blowout, loss of vehicle control, and jackknife on highways. (5) When to refuse to drive — Empower drivers to decline a dispatch if pre-trip reveals any tire defect. Our inspection data shows Kenworth (7 citations), Volvo (4), and International-branded equipment (6 combined) are most frequently cited—consider make-specific training if your fleet operates these chassis.

File a DataQs challenge if: (1) The inspector's inspection report does not clearly describe which tire was flat or where the leak was heard/located. (2) The vehicle's maintenance records show that the tire was inspected and pressurized within 24 hours prior to the citation, and the driver's pre-trip report confirms condition. (3) The vehicle was parked and stationary when cited, and pressure loss could have occurred during idle time due to extreme temperature swing or a slow leak undetectable during normal operation. (4) Photos or witness statements contradict the citation. Our data shows no out-of-service orders from this code, so most citations are entered on the carrier's CSA record; a successful challenge can remove points. Gather repair records and pre-trip logs as supporting evidence.

Conduct monthly tire audits with a documented checklist. Our 90-day trend shows 8 citations in the most recent quarter, compared to 17 over the last 12 months—indicating higher concentration in recent months, with 6 citations in February 2026 alone. This pattern suggests seasonal or operational intensity variation. At minimum, audit: (1) All tire pressures fleet-wide (drive, trailer, spare); (2) A representative sample of pre-trip inspection reports for compliance and legibility; (3) Tire replacement/repair schedules to identify vehicles approaching mileage limits. Conduct an in-depth fleet-wide tire inspection every 90 days, and a quick walk-around daily as part of the lot safety check. Given the recent spike in citations, increase frequency until two consecutive months show zero defects.