# Service bulletin S21AZ

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10197678
- Published by NHTSA: 2021\-06\-18
- Manufacturer's number: S21AZ
- Manufacturer's date: 2021\-06\-10
- NHTSA component: ENGINE AND ENGINE COOLING

## NHTSA's summary

Overview: Certain 2013 through 2022 model year Blue Bird Vision School and Non\-School Bus units has experienced signs of single strand failing, leading to multiple stands, and eventually belt failure. The belt composition is not ideal for the life cycle of the bus. This Service Bulletin will provide owners with a one\-time new replacement belt with the more durable material that is currently being used in production and for service. This Service Bulletin is for part cost coverage only. No labor reimbursement will be provided. Affected Units: Blue Bird Body Company is voluntarily issuing a service bulletin for the following: o Certain model year 2013 through 2022 Blue Bird Vision School Buses omanufactured from January 10, 2012 through February 26, 2021 o Certain model year 2013 through 2022 Blue Bird Vision Non\-School Buses omanufactured from November 20, 2012 through November 19, 2020 Repair Parts: The Parts List outlined in the S21AZ Instructions details the part required to perform Service Bulletin S19AZ and should be ordered through Blue Bird Service Parts. The belt is based on the engine generation. Parts are currently available. Time Allowance: No labor will be provided to replace the belt with a more durable material belt, per the published Service Bulletin instructions.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10197678-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10197678-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- 2013 to 2019 BLUE BIRD VISION
- 2020 to 2022 BLUE BIRD VISION SCHOOL BUS
- 2020 to 2022 BLUE BIRD VISION TRANSIT BUS

JSON: [/v1/bulletins/10197678](/v1/bulletins/10197678)

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