If your VIN is in recall 21V017, Thomas Built Buses will inspect brake caliper bolts and repair them free at a Thomas Built Buses dealer.
Thomas Built Buses is recalling 6 2021 Saf-T-Liner Efx and Saf-T-Liner Hdx school buses because a driver-side steer axle brake caliper mounting bolt was not tightened correctly. Loose caliper bolts can reduce brake effectiveness and increase crash risk, and Thomas Built Buses dealers will complete the repair free of charge.
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What's wrong?
The caliper mounting bolts on these 2021 Thomas Built Buses Saf-T-Liner Efx and Saf-T-Liner Hdx school buses hold the brake caliper in place on the driver side steer axle. The caliper is the part of the air disc brake that squeezes the brake pads against the rotor when the driver applies the brakes. Those bolts keep the caliper fixed so the brake force is applied where it belongs.
On affected buses, one of the six caliper mounting bolts was not tightened correctly during assembly. A bolt with too little torque starts out less secure than designed. Testing found that if that bolt loosens, nearby caliper bolts can gradually loosen over time as the brake assembly moves under normal braking loads.
There is no warning sign before failure. A driver or fleet technician should not rely on feel from the pedal or a visible symptom to catch this defect before inspection.
Who's affected?
Covers the Saf-T-Liner Efx and Saf-T-Liner Hdx, both involving the hydraulic brake system.
| 2021 Thomas Built Buses Saf-T-Liner Efx | hydraulic brake system |
|---|---|
| 2021 Thomas Built Buses Saf-T-Liner Hdx | hydraulic brake system |
| Units affected | 6 |
| Field incidents | NHTSA has logged no field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether this recall applies to your specific bus.
What's the safety risk?
Loose brake caliper bolts can reduce clamping force between the brake caliper and anchor plate. That reduces brake effectiveness and increases the risk of a crash. If your VIN is included, schedule service soon and leave extra stopping distance until the bus is inspected. Repair is free at any franchised Thomas Built Buses dealer.
What should I do?
- Check your VIN to confirm your 2021 Thomas Built Buses Saf-T-Liner Efx or Saf-T-Liner Hdx is included in this recall.
- Contact your nearest franchised Thomas Built Buses dealer to schedule the free brake-caliper bolt inspection and any needed repair for the driver-side steer axle.
- Bring the recall notice if you have it. If not, reference recall number 21V017 and DTNA recall FL-873 when you call.
- Drive cautiously until the repair is complete. Leave extra following distance and avoid hard braking.
- Call Thomas Built Buses customer service at 1-800-547-0712 with questions about scheduling or the repair.
What happens at the repair
At the dealer, a Thomas Built Buses technician inspects the driver side steer axle brake caliper mounting bolts, including the bolt identified in the recall, and repairs the brake caliper mounting hardware as needed. That work is free under the recall. The service desk can confirm whether the inspection is complete, what repair was performed, and whether any related brake hardware needed adjustment or replacement before the bus returns to service.
Timeline
| January 20, 2021 | NHTSA published the recall |
|---|---|
| March 17, 2021 | Owner notification mailed |
| March 19, 2021 | Dealer notification began |
| March 19, 2021 | Dealer notification ended |
| March 19, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V017?
Recall 21V017 covers 6 2021 Thomas Built Buses Saf-T-Liner Efx and Saf-T-Liner Hdx school buses with a driver-side steer-axle brake caliper mounting bolt that was incorrectly tightened. Thomas Built Buses dealers will inspect the brake caliper mounting hardware and repair it for free.
What should I do if my 2021 Thomas Built Buses Saf-T-Liner Efx or Saf-T-Liner Hdx is on this recall?
Check your VIN to confirm your specific school bus is included in recall 21V017. If it is, contact a franchised Thomas Built Buses dealer to schedule the brake caliper inspection and repair. Reference recall number 21V017 or DTNA recall FL-873 when you call.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost. For recall 21V017, Thomas Built Buses dealers will inspect the affected brake caliper mounting hardware and complete the needed repair free of charge.
What is the safety risk?
The safety risk is reduced brake effectiveness. A loose driver-side steer-axle brake caliper bolt can let other caliper bolts loosen, reducing clamping force between the brake caliper and brake anchor plate. That loss of braking performance increases crash risk.
When did the recall repair become available?
The recall began on March 17, 2021, so the dealer inspection and repair are available now. If your VIN is included, contact a franchised Thomas Built Buses dealer or DTNA customer service at 1-800-547-0712 and reference FL-873.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V017000 |
|---|---|
| Thomas Built Buses customer service | 1-800-547-0712 |
| NHTSA recall # | 21V017 |
| NHTSA recall # (full) | 21V017000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Recall Document (PDF) (PDF)
- Download Quarterly Report (PDF)
- Download Misc. Document (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 23, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →