Identifying Your Hydraulic Power Unit Maintenance Needs

For GSE crews, no piece of equipment is more important than their hydraulic power unit. These vital machines are an essential part of maintaining aircraft. When your power unit goes down, it can bring your business to a screeching halt. That’s why it’s so important to ensure that you have a hydraulic power unit maintenance plan in place from the moment you purchase your equipment. Establishing a plan before putting your equipment into service will keep your machine working in peak operating condition and sustaining high performance while limiting any downtime.

Reactive vs. Preventative Hydraulic Power Unit Maintenance

hpu repair and maintenance

When it comes to hydraulic power unit maintenance, there are two different categories: Reactive and preventative maintenance. In reactive maintenance, technicians spring into action only after a problem has occurred. Whether a part has broken or a leak has developed, these repairs are intended to restore a machine to working order only after experiencing issues.

Preventative hydraulic power unit maintenance, on the other hand, is intended to prevent parts from breaking, keeping your unit running uninterrupted. Not only does this prevent you from losing productivity, but preventative maintenance is also almost always much cheaper than repairing a machine after it’s broken. When you stick to a well-planned preventative maintenance schedule, you’ll end up saving yourself a ton of time and money.

Building a Hydraulic Power Unit Maintenance Program

There’s no single, universal way to set up a hydraulic power unit maintenance program. Equipment comes from a number of different manufacturers, and each model has different maintenance requirements. This means that it’s critical for you to pay attention to the manual for each individual machine to ensure that you’re applying the standards that are specific to that machine.

With this being said, there are a number of factors that are applicable to almost all hydraulic power unit maintenance programs. In general, the tasks can be divided into daily, monthly, bi-annual, and yearly tasks. By keeping meticulous records for each component of your maintenance tasks, you’ll be able to make sure that your equipment is receiving the attention it needs.

Daily Hydraulic Power Unit Maintenance Tasks


Daily preventative maintenance generally includes looking over your equipment and making sure that there are no developing problems. These tasks are usually quick and simple and should be performed prior to using the equipment for the day. Your daily preventative maintenance checklist may look something like this:

  • Inspect the oil level
  • Look for hydraulic fluid or oil leaks
  • Tighten any loose clamps or screws
  • Listen to the unit to see if any changes have occurred
  • Inspect temperature and pressure gauges
  • Clean excess dirt and grime from the unit
  • Look at the maintenance log to see whether any problems have occurred

It’s always a good idea to have a log sheet to ensure that these daily tasks are performed. It can also be a good way to keep a record of who has inspected the unit.

Monthly Hydraulic Power Unit Maintenance Tasks

Monthly tasks tend to take a little more time than daily maintenance. They are focused on eliminating any developing fluid leaks and keeping the system as free from contaminants as possible.

While daily tasks keep your unit running smoothly, monthly checks are intended to stop any developing problems in their tracks. Your monthly maintenance checklist may look like this:

  • Inspect filters
  • Clean and replace any strainers
  • Look for potential hydraulic fluid leaks
  • Tighten loose clamps, connections, fittings, or other points
  • Inspect cylinders and clean any visible dirt
  • Replace seals or pipes that may be leaking

Once you finish your monthly maintenance, be sure to log any repairs you performed in your maintenance book, in case someone needs to reference it later.

Bi-Annual Check-In

In addition to the monthly maintenance, every six months you should take an oil sample from your hydraulic power unit and send it out to be tested. This ensures that your oil is performing as expected, maintaining the right viscosity with limited particle counts, wear  

metals, and oxidation.

This is also a good time to look back at the maintenance log to see if there are any developing issues that need to be corrected. If you notice a problem that keeps recurring, this is an excellent time to take care of it once and for all.

Annual Hydraulic Power Unit Maintenance Tasks

Hydraulic power unit maintenance

Your yearly hydraulic power unit maintenance starts with the oil. The first step should be to drain the oil tank. If you’re planning to reuse the oil — which should only be done if it’s clearly still viable — then be sure to use clean containers to catch it.

Once the oil is drained, thoroughly clean the oil tank, removing any dirt, grime, and excess particles. You should use only cleaning solutions and cleaning tools recommended by the manufacturer to reduce any potential damage and avoid leaving particles behind. You should also take the time to flush pipes that run from the tank to eliminate build-up.

This is your opportunity to perform an entire system check. Inspect the motor couplings and the pump itself to make sure that everything is working as designed. You should also test every component in your hydraulic power unit at this point, repairing or replacing anything that may present a problem in the future.


Setting up your hydraulic power unit maintenance plan is relatively easy — simply pay attention to the manufacturer’s specifications and put everything in writing. What’s more important is making sure that you stick to the maintenance plan. All of the planning in the world won’t make a difference if your technicians don’t execute it.

Once you establish the preventative maintenance habit, though, your equipment should last much, much longer. You’ll avoid having to shell out for major repairs and putting more stress on your other machines, which would have to fill the void while those repairs were being performed.

FlyTek GSE

The best way to ensure that your hydraulic power units stay fully operational is to let FlyTek GSE establish a maintenance plan for your equipment. With our extensive experience in working with a wide variety of manufacturers, we know how to take care of your machines. Contact us today to set up your hydraulic power unit maintenance plan.