Violation code

393.48A-BMBC

All Brakes - Missing or Broken Components including Pad Retaining Components and loose or missing caliper mounting bolt(s)

Vehicle Maintenance4Non-OOS· SMS Appendix A v3.20

393.48A-BMBC is a Brakes, All Others violation under 49 CFR §393.48A-BMBC. It falls in the Vehicle Maintenance BASIC with a severity weight of 4/10. Nationally it was cited 6,287 times in the last five years, with an OOS rate of 22.1%.

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National roadside inspection stats

as of 6/20/2026

Inspections

5,500

that found this code

Violations

6,287

total written

OOS rate

22.1%

1,392 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 §: 393.48A-BMBC
Severity weight: 4
Used in SMS: Yes
Status: Active
Updated: 6/20/2026

Last updated June 2026

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Notes

DSMS: N | Comment: Updated description in 3.11 | Footnote: The description for this violation was updated in SMS with the September 25, 2020 snapshot.

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Challenging 393.48A-BMBC through FMCSA DataQs

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

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

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Codes under the same FMCSA violation group

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Frequently asked questions about 393.48A-BMBC

What does violation 393.48A-BMBC mean?

393.48A-BMBC is the FMCSA roadside-inspection violation code for "All Brakes - Missing or Broken Components including Pad Retaining Components and loose or missing caliper mounting bolt(s)", part of the Brakes, All Others group, cited under 49 CFR §393.48A-BMBC.

What BASIC does 393.48A-BMBC affect?

393.48A-BMBC falls under the Vehicle Maintenance BASIC in the FMCSA Safety Measurement System (SMS).

What is the CSA severity weight of 393.48A-BMBC?

393.48A-BMBC 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 393.48A-BMBC an out-of-service (OOS) violation?

No. 393.48A-BMBC 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 393.48A-BMBC add to a carrier's score?

The point contribution of 393.48A-BMBC 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.

Can 393.48A-BMBC be challenged through DataQs?

Yes. If you believe 393.48A-BMBC 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 393.48A-BMBC Vehicle Maintenance BASIC Carrier CSA lookup CSA glossary

393.48A-BMBC

National roadside inspection stats

Challenging 393.48A-BMBC through FMCSA DataQs

Pre-trip inspection showed compliant brakes

Momentary failure exception (§393.9)

Tread measurement disputed

Documented maintenance schedule disproves the defect