2017 PROTERRA CATALYST

STEERING:GEAR BOX (OTHER THAN RACK AND PINION)

Proterra, Inc. (Proterra) is recalling certain 2017-2019 35 foot Catalyst E2, 2017-2019 40 foot E2, 2020-2021 35 foot RR, 2019-2020 40 foot RR, 2019-2022 40 foot ZX5, and 2020-2022 35 foot ZX5 buses. The plexus adhesive between the torque limiter plate and the bus body may be insufficient, causing the bolts that secure the steering gearbox to loosen.

Risk: A loose steering gearbox can cause a loss of steering control, increasing the risk of a crash.

ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY

Proterra Operation Company, Inc. (Proterra) is recalling certain 2017-2019 Catalyst transit buses. One or more battery packs may allow liquid to leak into and accumulate in the battery pack enclosure.

Risk: The accumulation of liquid inside the battery pack enclosure increases the risk of a fire.

SERVICE BRAKES

Proterra, Inc. (Proterra) is recalling certain 2015-2018 Catalyst 40 buses equipped with an optional tow fitting and airline that allows a tow truck to operate the rear brakes on the vehicle. The mesh cap covering the airline for the tow fitting can be clogged with road debris in inclement weather, possibly resulting in a build up of air pressure in the rear brake system.

Risk: A build up of air pressure can cause the brakes to drag and possibly overheat, increasing the risk of fire.

SERVICE BRAKES, AIR:SUPPLY:RESERVOIR/TANK

Proterra Inc., (Proterra) is recalling certain 2015-2018 Catalyst 40 transit buses. The affected vehicles lack a Graham White air brake supply reservoir, possibly resulting in long term moisture build up in the air brake system. As a result, these vehicles fail to comply with Federal Motor Vehicle Safety Standard (FMVSS) number 121, "Air Brake Systems."

Risk: Built-up of moisture in the air brake system may lead to brake failure, increasing the risk of crash.

SERVICE BRAKES, AIR:SUPPLY:CHECK VALVE

Proterra, Inc. (Proterra) is recalling certain 2017-2018 Catalyst buses. The vehicles are equipped with swivel valves that may insufficiently protect the air brake system from an air leak between the service reservoir and the source of air pressure. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 121, "Air Brake Systems."

Risk: If the swivel valves are unable to protect the air brake system against loss of air pressure, this may lead to service brake failure and the possibility for the uncontrolled application of the safety brake. Either condition increases the risk of crash.

SUSPENSION:FRONT

Proterra Inc., (Proterra) is recalling certain 2015-2018 Catalyst 40 and 35 transit buses. The affected vehicles are equipped with a four point height control system that may cause a load imbalance, overloading the front tires.

Risk: An overloaded front tire may fail unexpectedly, increasing the risk of crash.

EQUIPMENT:OTHER:LABELS

Proterra, Inc is recalling certain 2015-2018 Catalyst 40, and Catalyst 35 buses. The certification label may list an incorrect gross front axle weight rating and/or incorrect tire pressures. As such, these vehicles fail to comply with the requirements of 49 CFR Part 567, "Certification."

Risk: If the tire pressure is understated, an underinflated tire may result in an increased risk of tire failure, increasing the risk of a crash.