Shop classes can give you a good indication of your mechanical aptitude and of whether or not you would enjoy maintenance work. The best way to experience the work these mechanics do, however, is to get a summer or part-time job as a maintenance helper in a factory, apartment complex, or similar setting. If such a job is not available, you might try talking with a maintenance mechanic to get a fuller, more complete picture of his or her responsibilities.

General maintenance mechanics perform almost any task that may be required to maintain a building or the equipment in it. They may be called on to replace faulty electrical outlets, fix air-conditioning motors, install water lines, build partitions, patch plaster or drywall, open clogged drains, clean and oil machinery, paint doors and woodwork, repair institutional-size dishwashers or laundry machines, and see to many other problems. Because of the diverse nature of the responsibilities of maintenance mechanics, they have to know how to use a variety of materials and be skilled in the use of most hand tools and ordinary power tools, as well have basic knowledge of computer systems. They also must be able to recognize when they cannot handle a problem and must recommend that a specialized technician be called.

General maintenance mechanics work in many kinds of settings. Mechanics who work primarily on keeping industrial machines in good condition may be called factory maintenance workers or mill maintenance workers, while those mechanics who concentrate on the maintenance of a building's physical structure may be called building maintenance workers and technicians.

Once a problem or defect has been identified and diagnosed, maintenance mechanics must plan the repairs. They may consult blueprints, repair manuals, and parts catalogs to determine what to do. They obtain supplies and new parts from a storeroom or order them from a distributor. They install new parts in place of worn or broken ones, using hand tools, power tools, and sometimes electronic test devices and other specialized equipment. In some situations, maintenance mechanics may fix an old part or even fabricate a new part. To do this, they may need to set up and operate machine tools, such as lathes or milling machines, and operate gas- or arc-welding equipment to join metal parts together.

One of the most important kinds of duties general maintenance mechanics perform is routine preventive maintenance to correct defects before machinery breaks down or a building begins to deteriorate. This type of maintenance keeps small problems from turning into large, expensive ones. Mechanics often inspect machinery on a regular schedule, perhaps following a checklist that includes such items as inspecting belts, checking fluid levels, replacing filters, oiling moving parts, and so forth. They keep records of the repair work done and the inspection dates. Repair and inspection records can be important evidence of compliance with insurance requirements and government safety regulations.

New buildings often have computer-controlled systems, so mechanics who work in them must have basic computer skills. For example, newer buildings might have light sensors that are electronically controlled and automatically turn lights on and off. The maintenance mechanic has to understand how to make adjustments and repairs.

In small establishments, one mechanic may be the only person working in maintenance, and thus may be responsible for almost any kind of repair. In large establishments, however, tasks may be divided among several mechanics. For example, one mechanic may be assigned to install and set up new equipment, while another may handle preventive maintenance.