By Michael Nielsen, Publisher | 15+ Years in Diesel Repair
Last Updated: October 2026
CVSA brake inspection standards are the brake-related criteria in the Commercial Vehicle Safety Alliance's North American Standard Out-of-Service Criteria, which certified inspectors apply together with federal regulations to decide whether a commercial vehicle's brakes present an imminent hazard. The most important is the 20 percent criterion: a vehicle goes out of service when 20 percent or more of its service brakes have an out-of-service condition.
This Heavy Duty Journal guide covers the federal rules behind those criteria, how the 20 percent rule works, pushrod stroke limits, air system checks, inspection levels, and a maintenance program that keeps brakes inside the limits. It reflects CVSA's 2026 criteria and rule changes through October 2026.
Key Takeaways
- ✓The criteria change every April. CVSA's 2026 Out-of-Service Criteria took effect April 1, 2026 and replaced all earlier editions, so a technician working from an older copy may be measuring to outdated language.
- ✓The 20 percent rule drives most orders. A vehicle is placed out of service when 20 percent or more of its service brakes have an out-of-service condition, which is why a few slightly out-of-adjustment brakes can ground a truck.
- ✓Measure every brake. Pushrod stroke limits depend on chamber type, so recording the stroke at each wheel position at each service catches drift before an inspector does.
- ✓Report handling changed in 2026. As amended in June 2026, 49 CFR 396.9 has carriers certify repairs within 15 days and keep a copy for 12 months, returning the form only if the issuing State agency requests it.
In This Guide
- What Are CVSA Brake Inspection Standards?
- Federal Brake Rules Behind the CVSA Criteria
- The CVSA 20 Percent Brake Rule and Out-of-Service Criteria
- Brake Adjustment and Pushrod Stroke Limits
- Air System and Brake Component Checks
- CVSA Inspection Levels and Roadside Reports
- Brake Safety Week Results and Common Violations
- Building a Brake Compliance Program
- Frequently Asked Questions
- The Bottom Line
What Are CVSA Brake Inspection Standards?
The Commercial Vehicle Safety Alliance (CVSA) is the non-profit alliance of enforcement agencies and industry whose out-of-service criteria (OOSC) set the pass-fail line for roadside inspections across North America. Certified enforcement personnel use the criteria to determine whether a driver or vehicle presents an imminent hazard and should be placed out of service, per CVSA's 2026 announcement.
The criteria are updated annually, effective April 1. The 2026 edition replaced all earlier versions and includes 17 changes, several of them in the brake section. Conditions for defective brakes and air brake hose were moved into the 20 percent criterion, the term "service gladhands" became "service air connections," and lining thickness measurements for hydraulic and electric brakes were aligned with the federal regulations.
CVSA sells the criteria in print and app formats, so confirm which edition your shop and drivers are using. A technician measuring to a pre-April 2026 copy can miss changes that matter on the roadside.
Federal Brake Rules Behind the CVSA Criteria
Federal brake requirements are the performance and maintenance rules in 49 CFR Parts 393 and 396 that the CVSA criteria help enforce. Part 393 sets equipment standards, including the service brake performance rule in 49 CFR 393.52, under which most non-passenger commercial vehicles must develop braking force of at least 43.5 percent of gross weight and decelerate at no less than 14 feet per second per second.
Part 396 governs inspection, repair, and maintenance. The table below summarizes the sections that matter most for brakes.
| Section | What It Requires | Timing or Retention |
|---|---|---|
| 49 CFR 396.3 | Systematic inspection, repair, and maintenance, with a record of each | Records kept 1 year where the vehicle is housed and 6 months after it leaves carrier control |
| 49 CFR 396.9 | Handling of roadside inspection reports: the driver delivers the report to the carrier, and the carrier certifies repairs | Certify within 15 days; keep a copy 12 months; return the form only if the issuing State agency requests it |
| 49 CFR 396.11 | Driver vehicle inspection reports (DVIRs) for defects, with the carrier certifying repairs before the vehicle runs again | Reports kept 3 months |
| 49 CFR 396.13 | Driver confirms the vehicle is safe to operate before driving, and reviews the last report | Before each trip |
| 49 CFR 396.17 and 396.19 | Periodic inspection by a qualified inspector at least once every 12 months, against the minimum standards in Appendix G to the Federal Motor Carrier Safety Regulations | Every 12 months |
| 49 CFR 396.21 | Periodic inspection report | Kept 14 months |
| 49 CFR 396.25 | Qualifications for people who inspect and repair brakes | Ongoing |
Two dates in that table are worth a note. 49 CFR 396.9 was amended in June 2026, and the periodic inspection report retention period is set in 49 CFR 396.21. HDJ's annual vehicle inspection requirements guide covers the periodic inspection in more detail.
The CVSA 20 Percent Brake Rule and Out-of-Service Criteria
The CVSA 20 percent criterion places a vehicle or combination out of service when 20 percent or more of its service brakes have an out-of-service condition, counted across every wheel position. It is the most-cited brake reason for out-of-service orders in CVSA's annual Brake Safety Week results.
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A brake counts as defective toward the 20 percent when it has an out-of-service condition such as stroke beyond the adjustment limit for its chamber type, a missing or inoperative component, an audible air leak at the chamber, or friction material below the minimum thickness. The 2026 edition also moved certain air hose and service air connection conditions into this criterion, so a disconnected service line is now counted instead of triggering an automatic order.
| Service Brakes on the Vehicle or Combination | Defective Brakes That Reach 20 Percent |
|---|---|
| 4 | 1 |
| 6 | 2 |
| 8 | 2 |
| 10 | 2 |
| 12 | 3 |
The table applies the 20 percent figure with fractions rounded up, which is how CVSA's criteria treat the count. A five-axle combination with 10 service brakes is therefore out of service with just two defective brakes, and a straight truck with four service brakes reaches the threshold with one.
Some conditions can place a vehicle out of service without reaching 20 percent, such as certain steering axle brake defects and air loss above the limit, and CVSA moves conditions between sections from year to year. Check the current criteria for how each condition is counted. Under 49 CFR 396.9(c), a vehicle marked out of service may not be operated, including towed, until the required repairs are completed, except by hoist or crane.
Brake Adjustment and Pushrod Stroke Limits
Pushrod stroke is the distance a brake chamber pushrod travels when the service brakes are applied, and it is the standard measure of whether a brake is in adjustment. Stroke beyond the limit for the chamber type counts as a defect toward the 20 percent criterion.
The measurement is made with the vehicle on level ground and the wheels chocked, the spring brakes released, and the air system charged to between 90 and 100 psi. Mark the pushrod at the chamber face with the brakes released, have an assistant fully apply the service brakes, and measure the distance the mark moves. Repeat at every wheel position.
⚠️ Safety Warning
Brake measurement involves pressurized air and moving linkage. Chock the wheels, keep hands and body clear of the pushrod and slack adjuster while an assistant applies the brakes, and never open or disassemble a spring brake chamber, which holds a compressed spring that can cause serious injury. Follow the manufacturer's procedure for any chamber work.
| Brake Chamber Type | Standard Maximum Stroke | Notes |
|---|---|---|
| Type 6 | 1¼ inches | Clamp-type chamber |
| Type 12 | 1⅜ inches | Clamp-type chamber |
| Type 20 | 1¾ inches | Long-stroke versions have a higher limit |
| Type 24 | 1¾ inches | A 3-inch maximum stroke Type 24 has a higher limit |
| Type 30 | 2 inches | Long-stroke Type 30 has a higher limit |
Those figures are the commonly published limits for standard clamp-type chambers, and the limit depends on the chamber type, size, and stroke rating marked on the chamber. Read the tag, then confirm the figure against the current edition of the criteria, because long-stroke and other chamber designs have different limits.
Automatic slack adjusters have been required on air-braked vehicles built since October 1994, but they do not replace measurement. A failed adjuster or worn foundation brake can leave stroke out of limit with the adjuster looking normal. HDJ's slack adjuster adjustment guide and S-cam brake adjustment technician guide cover the hands-on steps.
Air System and Brake Component Checks
Air system and component checks are the inspections of the compressed-air supply, hoses, chambers, and friction components that make a brake system work. Most heavy trucks use air brakes, while lighter commercial vehicles often use hydraulic brakes and some newer systems add electric components.
Inspectors look for audible air leaks at brake chambers, damaged or bulging hoses, and damage that exposes the hose reinforcement ply. The truck's low air pressure warning device is required under 49 CFR 393.51 to signal when pressure falls to 60 psi or one-half the governor cutout pressure, whichever is less.
Air loss is timed over one minute. CVSA's criteria set limits of 2 psi per minute for a single vehicle and 3 psi per minute for a combination with the brakes released, and 3 psi and 4 psi per minute with the brakes applied. Verify these against your current edition before using them as a shop standard.
Friction material has a minimum thickness in the criteria, and CVSA's 2026 edition amended the lining thickness measurements for hydraulic and electric brakes to align with federal regulations. Because the numeric minimums differ by brake type, take them from the current criteria rather than a shop poster.
CVSA's 2025 Brake Safety Week focused on drums and rotors and found 113 violations, 39 of which placed vehicles out of service, according to its published results. Air disc brakes, S-cam brakes, and hydraulic brakes each showed violations, so inspect friction surfaces as carefully as chambers.
Contamination causes many air system problems. Water in the air supply can freeze and block valves, and oil from a worn compressor or a failing air dryer can degrade seals and diaphragms. Drain tanks on schedule, replace air dryer cartridges per the manufacturer's interval, and trace any oil in the system to its source. HDJ's air brake system troubleshooting guide walks through diagnosis.
CVSA Inspection Levels and Roadside Reports
A North American Standard Level I inspection is CVSA's most thorough roadside inspection, a 37-step examination of driver credentials and the vehicle that includes the brake system. Other levels cover less: Level II is a walk-around, Level III is driver-only, and Level V is a vehicle-only inspection done without the driver present.
Some jurisdictions also use a performance-based brake tester (PBBT), which measures braking force against the 49 CFR 393.52 standard. CVSA reported that 15 states used PBBTs during 2025 Brake Safety Week. A vehicle that passes a Level I or Level V inspection with no critical violations may receive a CVSA decal.
After an inspection, the driver receives a Driver Vehicle Examination Report. Under the current 49 CFR 396.9(d), the driver delivers it to the carrier at the next terminal or facility, or transmits it right away if no such stop is expected within 24 hours. The carrier then certifies within 15 days that all violations were corrected, returns the form only if the issuing State agency asks, and keeps a copy for 12 months.
Brake Safety Week Results and Common Violations
Brake Safety Week is CVSA's annual enforcement event within its Operation Airbrake program, and its results show which brake conditions most often ground trucks. During the 2025 event, held August 24 to 30, inspectors conducted 15,175 commercial motor vehicle inspections and placed 2,296 vehicles out of service for brake violations.
15.1%
Share of vehicles placed out of service for brake-related violations during CVSA's 2025 Brake Safety Week (2,296 of 15,175 inspected), according to CVSA's published results.
| Brake Out-of-Service Violation (2025) | Violations |
|---|---|
| 20 percent defective brakes criterion | 1,199 |
| Other brake violations | 375 |
| Brake hoses and tubes | 306 |
| Steering axle brake violations | 199 |
The 20 percent criterion accounted for more than half of the vehicles placed out of service, which matches the HDJ view above: the common failure is several marginal brakes, not one broken one. The 2026 Brake Safety Week ran August 23 to 29, 2026, and CVSA typically publishes results in the fall, so check CVSA for the 2026 figures.
Building a Brake Compliance Program
A brake compliance program is the set of inspections, measurements, repairs, and records that keep every brake inside its limits between roadside inspections. It starts with inspecting more often than the 12-month periodic minimum, since fleets that wait for the annual inspection find problems only once a year.
At each service, record the pushrod stroke at every wheel position, along with lining or pad condition and any air leaks. Written numbers let a technician see which brakes are drifting toward their limits and replace components before they reach them, instead of after an inspector finds them.
Drivers are the first check. Under 49 CFR 396.13 they confirm the vehicle is safe before driving and review the last report, and under 49 CFR 396.11 defects go on a DVIR that the carrier certifies as repaired before the vehicle runs again. Train drivers on what an out-of-service brake looks and sounds like, not only on the paperwork.
| Record | Minimum Retention | Rule |
|---|---|---|
| Driver vehicle inspection report and repair certification | 3 months | 49 CFR 396.11 |
| Roadside inspection report copy with carrier certification | 12 months | 49 CFR 396.9 |
| Periodic (annual) inspection report | 14 months | 49 CFR 396.21 |
| Vehicle maintenance records | 1 year, plus 6 months after the vehicle leaves carrier control | 49 CFR 396.3 |
Qualified people matter as much as records. The periodic inspection must be done by an inspector who meets 49 CFR 396.19, and people who inspect or repair brakes must meet 49 CFR 396.25. HDJ's heavy-duty brake maintenance guide covers building the maintenance schedule itself.
Frequently Asked Questions
What are CVSA brake inspection standards?
CVSA brake inspection standards are the brake criteria in the North American Standard Out-of-Service Criteria. Certified inspectors apply them with federal regulations to decide whether a vehicle must be placed out of service. The criteria are updated every year, effective April 1, and the 2026 edition replaced all earlier versions.
What is the CVSA 20 percent brake rule?
The 20 percent rule places a vehicle or combination out of service when 20 percent or more of its service brakes have an out-of-service condition, counted across all wheel positions. Stroke beyond the limit, missing components, and air leaks at the chamber are examples. It was the most-cited brake violation in 2025 Brake Safety Week.
What is the pushrod stroke limit for a Type 30 brake chamber?
The commonly published limit for a standard clamp-type Type 30 chamber is 2 inches, and long-stroke versions have a higher limit. Because limits depend on chamber type and design, read the chamber tag and confirm the figure in the current edition of the out-of-service criteria.
What happens after a roadside inspection report is issued?
The driver delivers the report to the carrier at the next terminal, or transmits it within 24 hours. The carrier certifies within 15 days that violations were corrected, keeps a copy for 12 months, and returns the form only if the issuing State agency requests it, under 49 CFR 396.9 as amended in June 2026.
How often must commercial vehicle brakes be inspected?
Brakes are covered by the periodic inspection, which must be done at least once every 12 months by a qualified inspector under 49 CFR 396.17. Drivers also check the vehicle before each trip, and carriers must keep a systematic maintenance program under 49 CFR 396.3, so brake checks are far more frequent than the annual minimum.
When do the CVSA out-of-service criteria change?
CVSA updates the criteria annually, effective April 1. The 2026 edition took effect April 1, 2026, replaced all previous versions, and contained 17 changes, including several in the brake section. Confirm the edition in use at your shop each spring, since older copies can contain outdated language.
The Bottom Line
CVSA brake inspection standards come down to a few measurable things: stroke within the limit at every wheel position, intact hoses and chambers, adequate friction material, and an air system that holds pressure. The 20 percent criterion means small drifts across several brakes can ground a truck as surely as one failure.
Heavy Duty Journal's guidance at heavydutyjournal.com, from publisher Michael Nielsen and the HDJ editorial team, is to measure and record every brake at every service, work from the current edition of the criteria, and treat the annual inspection as a floor rather than a schedule.
As of October 2026, the 2026 criteria and the amended 49 CFR 396.9 are in effect, so confirm the numeric limits for your chamber types and brake designs against the current criteria before you build shop standards around any figure in this guide.
Send This to Your Shop Foreman
Know a technician or fleet maintenance manager still working from a pre-2026 copy of the out-of-service criteria? Pass this guide along so brake checks match the current edition.
