Hydraulic power units (HPUs), a type of ground support equipment, are crucial for the testing and maintenance of aircraft systems. But like any machine, they cannot be used if they are not in peak condition. This is where preventative maintenance comes into play. By maintaining your HPU prior to its breaking down, you will be able to rely on it whenever you need it. In this blog, we will look at the four most important aspects of HPU maintenance: checking and changing oil, cleaning filters and strainers, checking for leaks, and lubricating the motor.