Violation code

393.45D-BAAL

Air Brake - Audible air leak at other than a proper connection.

Vehicle Maintenance4Non-OOS· SMS Appendix A v3.20

393.45D-BAAL is a Brakes, All Others violation under 49 CFR §393.45D-BAAL. It falls in the Vehicle Maintenance BASIC with a severity weight of 4/10. Nationally it was cited 26,855 times in the last five years, with an OOS rate of 87.7%.

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National roadside inspection stats

as of 10/20/2026

Inspections

25,794

that found this code

Violations

26,855

total written

OOS rate

87.7%

23,558 OOS

Source: FMCSA roadside inspection data (last 5 years). The OOS rate is the share of these violations that led the officer to mark the driver or vehicle out of service.

Violation group: Brakes, All Others
Regulation §: 393.45D-BAAL
Severity weight: 4
Used in SMS: Yes
Status: Active
Updated: 10/20/2026

Last updated October 2026

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Notes

DSMS: Y | Comment: Added in 3.15 | Footnote: As of February 1, 2023, the violations in this table are included in SMS. Only violations cited on or after February 1 are included in SMS calculations. This update aligns SMS with how violations are being cited in a new software used for roadside inspections.

What 393.45D-BAAL means — and how to avoid it

In plain English

In plain terms, 393.45D-BAAL is cited for air Brake - Audible air leak at other than a proper connection. It falls under the FMCSA rules on parts and accessories needed for safe operation.

What the inspector checks

•Brake adjustment and pushrod stroke within limits
•Air loss/leaks, low-air warning, and reservoir pressure
•Cracked, worn, or contaminated linings, drums, and rotors
•Hoses/tubing chafing, kinked, or leaking

How to prevent it

✓Check brake adjustment and listen for air leaks at every pre-trip
✓Fix air leaks and warning-light faults before dispatch — don’t “drive it in”
✓Put brakes on the PM schedule and document the work

How it affects your CSA

up to 12 pts (fresh)

Severity 4/10. A fresh citation counts at the 3× time weight — up to 12 points toward the Vehicle Maintenance BASIC — then tapers to 2× after 6 months and 1× after a year, dropping off the score at 24 months.

General guidance from the violation’s FMCSA classification — not legal advice, and not a substitute for the inspector’s findings or 49 CFR.

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Challenging 393.45D-BAAL through FMCSA DataQs

If this violation was written incorrectly, here are the angles trucking-safety managers use to contest it. Playbook: Vehicle Maintenance (general).

Relevant 49 CFR49 CFR § 393.45

Brake tubing and hose; adequacy

“All brake tubing and hose must: be designed and constructed in a manner that ensures proper, adequate, and continued braking action; be installed in a manner that prevents chafing, kinking, or other mechanical damage; be installed in a manner that prevents undue heating from contact with the vehicle's exhaust system.”

Common ways to challenge this code

Pre-trip inspection showed compliant brakes
The driver's pre-trip DVIR documented compliant brake adjustment and operation. The cited defect arose en route or was misclassified at roadside.
Evidence that wins
- ✓Driver Vehicle Inspection Report (DVIR) from that date
- ✓Repair invoice or shop record
- ✓Post-citation re-inspection certificate (clean)
Momentary failure exception (§393.9)
The required lamp was inoperative only momentarily due to vibration, temperature, or similar transient cause — explicitly exempted under §393.9.
Evidence that wins
- ✓Photograph showing the lamp operable before / after the stop
- ✓Repair invoice if a fuse or bulb was replaced
Tread measurement disputed
The tread depth measurement was taken at a worn point that is not representative, contrary to NHTSA/FMCSA measurement standards.
Evidence that wins
- ✓Independent tread gauge reading from same tire (multiple positions)
- ✓Photograph of the tire with a reference scale
Documented maintenance schedule disproves the defect
Carrier's periodic-inspection records show the cited defect could not reasonably have existed at the time of inspection.
Evidence that wins
- ✓Periodic inspection certificate (§396.17)
- ✓Maintenance work order proximate to inspection date

Common pitfalls — avoid these

⚠DataQs cannot remove a violation simply because the defect was repaired after the stop

⚡ Draft a challenge for 393.45D-BAAL →Read the DataQs guide first

More codes in Vehicle Maintenance

Same BASIC category — ranked by national citation volume

View all Vehicle Maintenance codes →

Other Brakes, All Others codes

Codes under the same FMCSA violation group

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Frequently asked questions about 393.45D-BAAL

What does violation 393.45D-BAAL mean?

393.45D-BAAL is the FMCSA roadside-inspection violation code for "Air Brake - Audible air leak at other than a proper connection.", part of the Brakes, All Others group, cited under 49 CFR §393.45D-BAAL.

What BASIC does 393.45D-BAAL affect?

393.45D-BAAL falls under the Vehicle Maintenance BASIC in the FMCSA Safety Measurement System (SMS).

What is the CSA severity weight of 393.45D-BAAL?

393.45D-BAAL carries a severity weight of 4 out of 10. Higher weights indicate violations more closely tied to crash risk, and they count more toward a carrier's Vehicle Maintenance score.

Is 393.45D-BAAL an out-of-service (OOS) violation?

No. 393.45D-BAAL is not an out-of-service violation, so on its own it does not trigger an out-of-service order at the roadside.

How many CSA points does 393.45D-BAAL add to a carrier's score?

The point contribution of 393.45D-BAAL depends on its severity weight (4/10) multiplied by a time weight of 3, 2, or 1 based on how recent the inspection is. You can calculate the exact contribution with the CSA points calculator.

How can a driver prevent 393.45D-BAAL?

Check brake adjustment and listen for air leaks at every pre-trip; Fix air leaks and warning-light faults before dispatch — don’t “drive it in”; Put brakes on the PM schedule and document the work.

Can 393.45D-BAAL be challenged through DataQs?

Yes. If you believe 393.45D-BAAL was recorded in error, you can file a Request for Data Review (RDR) through the FMCSA DataQs system with supporting evidence. A successful challenge can remove or correct the violation on your record.

Keep going

CSA points calculator How to challenge a violation Draft a DataQs letter for 393.45D-BAAL Vehicle Maintenance BASIC Carrier CSA lookup CSA glossary

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