Alexander Dennis Enviro 500 2024 — technical service bulletin
Bulletin TMP500001.00 · NHTSA communication 11035222 · issued Jul 31, 2026
Technical service bulletin
communication type
Engine
component
2024
model years
1
vehicle entries
Official summary
This procedure defines the requirements and methodology for flushing and cleaning the driveline coolant circuits of an Enviro 500 DSL double deck bus, including the engine cooling circuit, gearbox cooling circuit, radiator, and header tank, following contamination by grease, oil, degraded coolant, or particulate matter.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.