2017–2018 Thomas Built Buses Saf-T-Liner Efx Recall: Check valve for the air brake system may not be plumbed correctly which…
NHTSA campaign 18V409000 · Service Brakes, Air · filed Jun 15, 2018 · verified Jul 30, 2026
The defect
Daimler Trucks North America LLC (DTNA) is recalling certain 2017-2018 Thomas Built Buses Saf-T-Liner EFX school buses. The check valve for the air brake system may not be plumbed correctly which can cause the primary air system to not be isolated from the secondary air system.
The risk
In the event of a rapid loss of air pressure in the secondary system, the incorrectly plumbed check valve can cause rapid air loss in both secondary and primary system, causing the parking brakes to activate suddenly. This will increase the risk of a crash.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →The fix — what to do
DTNA will notify owners, and dealers will inspect and repair the check valve as needed, free of charge. The recall began on August 12, 2018. Owners may contact DTNA customer service at 1-800-547-0712. DTNA's number for this recall is FL-774.
Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.safercar.gov.
Affected vehicles
| Make | Model | Model years |
|---|---|---|
| Thomas Built Buses | Saf-T-Liner Efx | 2017, 2018 |
Related recalls
More Thomas Built Buses Saf-T-Liner Efx recalls
- 2023–2026 Thomas Built Buses Saf-T-Liner Efx and 1 other model — Heater hose clamps may not have been tightened properly…
- 2023–2025 Thomas Built Buses Saf-T-Liner Efx and 1 other model — Heater hose clamps may not have been tightened properly…
- 2025–2027 Thomas Built Buses Minotour DRW and 4 other models — Wheel chair restraint retractor may not lock, preventing…
- 2025–2026 Thomas Built Buses Saf-T-Liner C2 and 4 other models — Tie rod castle nut and cotter pin may not be installed…
- 2019–2022 Thomas Built Buses Minotour DRW and 5 other models — Emergency Exit Label lettering is too small and may be…
Other campaigns involving Thomas Built Buses vehicles
- 2026–2027 Thomas Built Buses Saf-T-Liner EFX2 and 1 other model — Entrance door may fail to open or close when the switch is…
- 2026–2027 Thomas Built Buses Saf-T-Liner HDX2 — Entrance door may fail to open or close when the switch is…
- 2027 Thomas Built Buses Saf-T-Liner HDX2 — Front and mid-body interior joints may have been…
All Thomas Built Buses Saf-T-Liner Efx recalls → · All Thomas Built Buses recalls →
Source: NHTSA recall database, campaign 18V409000 (manufacturer number FL-774). Data last verified Jul 30, 2026.