A brake inspection checklist that measures like an inspector
Inspectors check brakes in a fixed order and measure them against fixed numbers. Use the same order and the same numbers in your yard, and a brake that would fail at the roadside gets fixed on your schedule.
Written by Gabriel Gonzalez
The brake check in numbers
A CVSA brake inspection checklist follows Operation Airbrake's 11 steps: check the mechanical parts, including the steering-axle brakes, bring air to 90 to 100 psi, measure every pushrod against its chamber's limit, then test the tractor protection system, ABS lamps, low-air warning, and air loss. Run it in your yard before an inspector does.
A truck placed out of service for brakes can't be driven until the repair is done, and the load waits with it. Most of those brakes could have been measured in your own yard the week before, with chocks, chalk, and a ruler.
I have spent more than 22 years at Simplex, nearly 16 of them as COO. This checklist follows the order a CVSA inspector uses, with the number that decides each item, so your shop's time goes to the brakes that would actually fail.
The full briefing, read aloud
8 chapters. Select one to jump to it.
Generated with AI text-to-speech from this article's key insights, in order, rather than reading it word for word. Chapter times come from a transcript of the audio. The article itself was written and reviewed by Gabriel Gonzalez.
Key takeaways
CVSA's brake check has 11 steps
Mechanical parts, steering-axle brakes, air pressure, stroke, tractor protection, ABS, low-air warning, air loss, and the paperwork.
Stroke limits depend on the chamber
A standard Type 30 chamber allows 2 inches of pushrod stroke; a long-stroke Type 30 allows 2 1/2. Identify every chamber before you measure.
The rated stroke on the tag is not the limit
CVSA describes it as the stroke where brake force drops to zero. Use the regulation's readjustment limit.
Don't just re-adjust an automatic adjuster
Federal inspection standards require finding and fixing why it went out of adjustment first.
Log the stroke at every wheel end
Readings with a date and odometer show a brake drifting toward its limit before it crosses it.
In this articleContents
What is on the CVSA brake inspection checklist?
The CVSA brake inspection checklist is the Operation Airbrake inspection procedure: 11 steps inspectors use to check air brakes. Steps 1 and 2 cover choosing a site and safety. The rest are checks your shop can copy.
| Step | What is checked | Fails when |
|---|---|---|
| 3 | Air brake mechanical components | Parts missing, loose, broken, or cracked; linings worn; hoses damaged |
| 4 | Steering-axle air brakes | The same defects, on the axle that steers |
| 5 | Air pressure brought to 90-100 psi | Setup for the stroke check |
| 6 | Brake adjustment | Pushrod stroke over the chamber's readjustment limit |
| 7 | Tractor protection system | It doesn't work automatically between 20 and 45 psi |
| 8 | ABS, if equipped | A malfunction lamp that never lights or stays on |
| 9 | Low air pressure warning | No warning at 55 psi, or half the governor cut-out if lower |
| 10 | Air loss rate | Air lost faster than the allowed rate |
| 11 | Paperwork | Results go to the driver, including any out-of-service order |
CVSA's own summary notes that the air loss rate is tested if a leak is detected. The same brake checks also sit inside a full inspection; our Level 1 inspection checklist covers the driver's documents and the rest of the truck.
What do you need before you start a brake inspection?
You need four tools and a fixed setup. CVSA's S-cam brake inspection checklist lists the tools:
- Wheel chocks in front of and behind the drive-axle wheels, or the trailer wheels if the trailer isn't coupled
- Chalk or soapstone to mark the pushrods, or the truck's external stroke indicators
- A measuring tool for pushrod stroke and lining thickness
- A brake application device, or a second person to hold the brakes on
Then park on level ground, chock the wheels, release the spring brakes, bring the air pressure to 90 to 100 psi, turn off the engine and remove the keys, and confirm each pushrod sits in its normal released position.
One number differs between the shop and the roadside. Appendix A to Part 396, the federal annual inspection standard, measures stroke at 80 to 90 psi. CVSA inspectors use 90 to 100 psi. Measure at the inspector's pressure, so your reading matches the one taken at the roadside.
How do you measure pushrod stroke?
Mark each pushrod where it leaves the chamber, make a full brake application, and measure how far the mark moved. Then compare that stroke with the limit for that chamber's type, not with a general number.
Step 1: Identify each chamber
The type is the chamber's size, such as 24 or 30. CVSA's pushrod stroke brochure notes that long-stroke chambers carry an "L" or a stroke tag, and some have square air ports. A long-stroke chamber has a higher limit, so a wrong guess gives a wrong answer either way.
Step 2: Mark the pushrod and apply the brakes
Scribe each pushrod at the chamber face, or use the external stroke indicator. Have your helper or an application device make and hold a full service application, and listen for leaks on the service side while it is held.
Step 3: Measure and compare
Measure from the mark back to the chamber face. Any brake over its readjustment limit in 49 CFR 393.47(e) is a violation.
| Chamber type | Standard stroke | Long stroke |
|---|---|---|
| Type 12 | 1 3/8 in. | 1 3/4 in. |
| Type 16 | 1 3/4 in. | 2 in. |
| Type 20 | 1 3/4 in. | 2 in., or 2 1/2 in. with a 3 in. rated stroke |
| Type 24 | 1 3/4 in. | 2 in., or 2 1/2 in. with a 3 in. rated stroke |
| Type 30 | 2 in. | 2 1/2 in. |
| Type 36 | 2 1/2 in. | None listed |
Bolt-type, rotochamber, and Bendix DD-3 chambers have their own limits in the same section. For a chamber that isn't listed, stroke may not exceed 80% of the rated stroke marked on it, or the readjustment limit its manufacturer marked on it.
Why the rated stroke is not the limit
Some chambers are tagged with the manufacturer's rated stroke, which is longer than the legal limit. CVSA describes it as the stroke at which brake force drops to zero, and says it should never be used as the adjustment limit.
New linings are a second trap. CVSA warns that drum brakes with new linings that haven't fully seated can go past the limit on a full application, so check them regularly after a reline.
What if a brake is out of adjustment?
Find out why before anyone touches the adjuster. Air-braked vehicles built on or after October 20, 1994, must have automatic adjusters (49 CFR 393.53). Appendix A to Part 396 says it is not acceptable to manually adjust one without first correcting the underlying problem, such as worn bushings, loose mounting hardware, or a cracked drum. An automatic adjuster swapped for a manual one fails the annual inspection outright.
CVSA's checklist is blunt: if the brakes are out of adjustment, don't adjust them; have a trained brake technician check and repair them before the truck goes back on the road.
What fails in the mechanical check?
The mechanical check is visual: every wheel end, with the steering axle checked on its own, before any air test. Look for:
- Missing, broken, or loose parts: shoes, linings, springs, anchor pins, cam rollers, pushrods, chamber mounting bolts, spiders, and camshaft brackets
- Camshaft play: too much up-and-down or sideways movement, a sign of missing bushings
- Linings and pads: loose on the shoe, soaked with oil or grease, cracked, or below the minimum thickness
- Drums and rotors: external cracks that open when the brake is applied, missing pieces, or rust that suggests the brake isn't working
- Chambers: rust holes, and audible leaks on the emergency side with the brakes released
- Hoses and tubing: lines rubbing on each other or on other parts, worn to a smaller diameter, or damaged through the outer reinforcement ply
- Matching sides: chambers of the same size and slack adjusters of the same effective length on each end of an axle
One lining number is worth knowing. At the roadside, a steering-axle air drum brake with a continuous strip of lining is legal down to 3/16 in. at the shoe center (49 CFR 393.47(d)). The annual inspection standard rejects any steering-axle drum lining under 1/4 in. Use 1/4 in. on every air drum brake in your shop, and 1/8 in. on air disc pads.
Drums and rotors were CVSA's 2026 focus; our Brake Safety Week guide covers what inspectors treat as a worn rotor. For damaged hoses and the air loss allowed in one minute, see our post on California roadside brake violations.
Which air system tests finish a brake inspection?
Four tests finish the inspection, CVSA steps 7 to 10, and each has a number in the federal rules.
Tractor protection system
On a tractor pulling an air-braked trailer, the tractor protection valve must operate automatically when tractor air pressure falls to between 20 and 45 psi. The trailer's emergency brakes must be activated automatically in that range, and also by a manual control in the cab (49 CFR 393.43).
ABS malfunction lamps
ABS is required on air-braked tractors built on or after March 1, 1997, and other air-braked vehicles built on or after March 1, 1998. The malfunction lamp must light when power is first applied and then go off; one that never lights, or stays lit, fails. Power units built after March 1, 2001, have two lamps, one for the power unit and one for the units it tows, and both must work.
Low-air warning
The warning must activate at 55 psi and below, or at half the governor cut-out pressure, whichever is less. A missing or inoperative warning fails.
Air loss rate and brake testers
If the inspector detects a leak, the air loss rate is tested next. Some inspection sites also use a performance-based brake tester, which measures brake force at each wheel against the vehicle's weight.
Trucks over 10,000 pounds GVWR must develop braking force of at least 43.5% of their weight (49 CFR 393.52). CVSA notes that a wheel end showing less than 43.5% on the printout likely has a problem, even when no violation is written.
Who should run the checklist, and what should you record?
Anyone responsible for inspecting, adjusting, or repairing your brakes must be a qualified brake inspector under 49 CFR 396.25: someone who understands the task and can do it, through an approved program, a state certificate, or at least one year of brake training or experience. Keep the evidence while they do the work, and for one year after.
There is one shortcut. You don't need those records for air brake inspections done by someone who passed the CDL air brake knowledge and skills tests. It covers inspections only, not adjustments or repairs.
Record the stroke at every wheel end
CVSA suggests a stroke log: the date, the odometer, and the measured stroke at each wheel end, every time you measure. In its example, one drive brake on a 2 1/2 in. limit reads 1 1/2 in., then 2 1/4 in., then 2 3/4 in. over about six weeks. The 2 1/4 in. reading was the warning.
Those readings belong in the maintenance file too. Federal rules require a record of the date and nature of every inspection and repair, kept for 1 year and for 6 months after the vehicle leaves your control (49 CFR 396.3). Our guide to FMCSA maintenance records shows what each entry needs.
Does a Texas state inspection check brakes the same way?
It checks them under the federal rules. Texas Transportation Code 548.201 requires Texas-registered commercial motor vehicles to pass an annual inspection of all the safety equipment the federal motor carrier safety regulations require, brakes included, under a program that meets those regulations. That covers trucks over 26,000 pounds and interstate trucks over 10,000 pounds registered in Texas. The fee is $50.
Under 49 CFR 396.17(f), a state periodic inspection that meets the Appendix A standards counts as the federal annual inspection for 12 months. Our Texas DOT compliance page covers the state's other requirements.
How Simplex helps you keep brakes inspection-ready
The measurements happen in your shop. The program, the qualifications, and the records around them are where we help.
Inspection and maintenance requirements
Our DOT safety compliance services cover the systematic inspection, repair, and maintenance program FMCSA expects, including annual inspections and the records behind them.
Annual inspections and records, tracked
Our compliance programs include annual inspection tracking, vehicle preventive maintenance records, and a DOT mock audit.
Where brake violations land
Roadside brake violations count in the Vehicle Maintenance BASIC. Our CSA program page explains how those results rank your company.
Frequently asked questions
What does a CVSA brake inspection check?+
At what air pressure do you check brake stroke?+
Can a driver adjust automatic slack adjusters?+
Who is qualified to inspect truck brakes?+
What are the Texas state inspection brake requirements for trucks?+
Where this information comes from
The requirements below come from federal regulations, CVSA's Operation Airbrake materials, and Texas law, checked on October 19, 2026.
-
1
eCFR — 49 CFR 393.47
Pushrod stroke readjustment limits by chamber type, lining and pad minimums, and matching chambers and slack adjusters.
-
2
eCFR — Appendix A to Part 396
The periodic inspection brake standards: stroke measured at 80 to 90 psi, lining limits, ABS lamps, low-air warning, and automatic adjusters.
-
3
eCFR — 49 CFR 393.43
The tractor protection valve and trailer emergency brakes, working automatically between 20 and 45 psi.
-
4
eCFR — 49 CFR 396.25
Who may inspect, adjust, or repair brakes, and the qualification records a carrier keeps.
-
5
CVSA — Operation Airbrake Inspection Procedure
The 11 steps inspectors follow in an air brake inspection.
-
6
CVSA — S-Cam Brake Inspection Checklist (PDF)
Tools, setup at 90 to 100 psi, what to inspect, and the advice not to adjust automatic brakes.
-
7
CVSA — Air Brake Pushrod Stroke Brochure (PDF)
Chamber identification, why rated stroke is not the limit, new linings, and the wheel-end stroke log.
-
8
Texas Transportation Code, Chapter 548
Texas's annual commercial motor vehicle inspection program and its $50 fee.
Written by
Gabriel Gonzalez
Chief Revenue Officer, Simplex Group
Chief Revenue Officer at Simplex Group, with more than 22 years at the company, including nearly 16 years as Chief Operating Officer. His background combines revenue strategy with deep operational experience, giving him a strong perspective on how compliance, risk, permits, cash flow, and operational readiness affect a carrier's ability to grow profitably.
Published · Updated
Related articles and services
Measure your brakes before an inspector does
Every item on this checklist has a number, and almost every number can be checked in your yard with chocks, chalk, and a ruler.
If you want help building the inspection routine and the records behind it, talk to our team.