Keeping power packs running smoothly through clean fluid

07 July, 2025

A technician connects a hydraulic line to a skimmer unit, highlighting the vital role of fluid cleanliness and maintenance in ensuring hydraulic power packs reliably deliver the pressure and flow needed to operate such equipment.

Hydraulic systems don't often fail suddenly. Most problems build up slowly, and fluid contamination is usually at the centre of it. It doesn’t get much attention because it isn’t obvious. There’s no dramatic breakage. But it’s the most common reason hydraulic power packs become unreliable, inefficient, or need early replacement.

Contamination tends to be treated as background noise. It’s understood in theory but rarely prioritised in day-to-day maintenance. It enters power packs in quiet, routine ways — from filling up with oil that’s been stored in an open container, or using a funnel that wasn’t properly cleaned, or simply through a worn breather letting in moisture and dust. Once inside, it moves with the oil through the pump, control valves, and any downstream circuits, slowly wearing down parts that were designed to run clean.

Because hydraulic power packs are usually seen as self-contained and reliable, there’s often an assumption that if it’s running, it must be fine. But these units operate on tight tolerances. Even small particles — metal from internal wear, rubber from seals, dust from the
environment — can cause lasting damage over time. They scratch surfaces, block ports, and disrupt valve performance. If water enters the reservoir, corrosion and fluid breakdown soon follow. In compact power packs where cooling is limited and filtration capacity is modest, the effect is more concentrated and often more severe.

This usually plays out in familiar ways: the system runs hotter, the response slows, pressure drifts. Valves  begin to stick. The motor draws more current. Eventually a pump fails, or a seal blows, and the pack is brought in for repair or replacement. At that point, the contaminated oil may have already been changed, but the damage is done. And without addressing the original cause — the contaminated fluid — the new parts are at risk from day one.

What’s frustrating is how avoidable most of this is. Keeping oil clean isn’t a technical challenge. It’s about doing basic things consistently. Oil should be stored sealed, indoors, away from dust and moisture. Filling should be done using clean, dedicated tools. Filters should be monitored and replaced based on operating conditions, not guesswork. And perhaps most overlooked — fluid should be tested. Sampling and analysis reveal what’s really happening inside the system and give early warning signs before
problems develop.

Mobile or remote installations

In mobile or remote installations, where power packs are often used, this kind of attention to fluid condition becomes even more critical. Access is harder, response times are slower, and the cost of failure is higher. The whole point of using a compact power unit is to provide reliable, self-sufficient hydraulic power — but when fluid care is left to chance, that reliability quickly
disappears.

Modern power packs are often designed with better filtration and even condition-monitoring options built in. But too often, these features are underused. Off-line filtration ports go unused. Filters go unchanged. Breathers are left open to the elements. And because the units are compact and “plug-and-play,” maintenance gets deferred. The result is that many power packs are running well below their intended lifespan — not because of design flaws, but because the fluid that runs through them wasn’t
looked after.