Veh Brake System Compliance Checks

---
name: veh-brake-system-compliance-checks
description: |
  Use this skill for vehicle brake system inspection requirements. Covers daily DVIR, weekly maintenance, brake adjustment check, and the 'percent of out-of-adjustment' rule.
---

# Brake System Compliance Checks

Brake system is the #1 cited area in roadside inspections. § 393.40 sets construction standards; § 396.3 and § 396.17 set maintenance and inspection.

## What brake checks must occur
1. **Pre-trip** (§ 392.7) — every trip
2. **Post-trip (DVIR)** (§ 396.11) — every duty day
3. **Annual inspection** (§ 396.17) — comprehensive
4. **Periodic inspection** between annuals — carrier's program (typically every 30-90 days)

## Pre-trip brake check
- Air pressure builds + holds (governor cuts off ~120 psi)
- Brakes work in service position
- Brakes work in spring (parking) position
- Brake light functioning
- Air drained from tanks weekly

## DVIR triggers for brakes
- Reduced braking distance
- Pulling to one side
- Squealing or grinding
- Air loss
- Brake light malfunction

## Annual inspection brake requirements
- Each axle brake performance test
- Slack adjuster check (within tolerance per FMCSA Appendix G)
- Brake hose and tubing integrity
- Brake shoe + drum measurements
- Wheel-end inspection for leaks

## Out-of-adjustment rule
A brake is considered "out of service" if more than 20% of brakes on a vehicle are out of adjustment. Compass + maintenance log should track this.

## Common brake violations
- Slack adjuster out of tolerance
- Brake hose contact with another component
- Brake shoe excessive wear
- Air pressure cutoff issues
- Anti-lock brake malfunction lamp on

## Compass tracking
Compass Vehicles module:
- Tracks annual inspection completion + next due
- Flags vehicles with documented brake issues
- Calculates carrier's brake-violation rate vs peer group

## CFR citations
- **49 CFR § 396.3**
- **49 CFR § 396.17**
- **49 CFR § 393.40**

## How Compass surfaces this
Searchable in Compass Ask. Runs against carrier fleet data when invoked from the relevant tracker. Read-only; no actions without explicit user approval.


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## Built by X3 Compass

The AI-powered DOT compliance platform for fleets 1–100 power units. Try a 7-day free trial — no credit card required — at https://x3compass.com/?utm_source=skill&utm_medium=github&utm_campaign=veh-brake-system-compliance-checks

X3 Compass turns these skills into a complete operational platform: driver qualification files, drug & alcohol consortium, MVR pulls, hours-of-service tracking, hazmat shipping, IFTA filing, FMCSA audit prep, and DataQ dispute drafting — all CFR-cited, all in one place.

*This skill is published under the X3 Compass open skills initiative. Contributions welcome at https://github.com/x3fleetsafety/skills*