They inspect, test, alter and repair diesel and gasoline engines, hybrid natural gas/electric engines/motors, inverters, high pressure fuel systems, clutches, transmissions, axles, generators, compressors, air conditioning systems, brake assemblies, door wheelchair lifts, and electrical and mechanical accessories, align, adjust and/or repair wheels, steering equipment and suspension systems; reline and adjust brakes and clutches; diagnose and repair modular automotive multiplex systems; operate power machine tools and portable power tools; use electronic diagnostic tools; use hand tools; record data and keep records; use computerized equipment; drive motor vehicles; may travel for training and vehicle inspection functions; and perform related work. Some of the physical activities performed by Bus Maintainers - Group B and environmental conditions experienced are: crawling under buses and working in confined areas; lifting and carrying heavy equipment; moving out of the way of moving buses and overhead cranes; manually removing and installing parts and bolts in confined areas; making visual inspections of equipment; distinguishing colors; reading gauges and prints; responding to sounds from warning bells, horns and vehicle movement; and working outdoors in all weather conditions.