Repairing and Maintaining Air Motors: A Primer

A familiar sight in industrial use and garage workshops alike, air motors are valuable for a variety of applications, having carved out a niche unfilled by electric or hydraulic power. It’s useful, then, to understand how they work—and what to do when they stop working. When your impact hammer or sander fails on you, being able to repair and renew it on your own can be handy.

The Basics of Air Motors

Pneumatic motors, also called air motors, use compressed air to generate mechanical work. Air motors fall under two categories: piston motors and rotary vane motors, which generate linear and rotary motion respectively. In either case, work is done by pumping compressed air and routing it through the motor such that it’s allowed to decompress; the energy released drives the piston or the shaft-mounted vanes, which act in turn on other components in the larger system. The primary advantage of air motors is simplicity, compact design and no need for electric charge.

Identifying Failure

The first step to repairing an air motor is identifying the cause of failure. A common cause can simply be an improperly-attached feed hose or a lack of lubrication. Using the motor for tasks that demand too high a load can damage internal components, resulting in strange pressure spikes. Assuming proper use of the motor, the most likely cause for a motor to unexpectedly lose power is clogging of internal components; in a work environment, unfiltered air can introduce debris or contaminants that halt or damage the motor.

Making Repairs

Because air motors are fairly simple, repair is straightforward if you have the right parts or a general-purpose Gast air motor rebuild kit. Most stock air motors can be brought back to life with common repair kits, which include a handful of replacement parts matching the model’s specifications as well as an instruction manual for disassembly and reassembly.

Regularly cleaning and lubricating air motors, and having the supplies on hand for quick repairs, can let your power tools go a long way.