Hydraulic system maintenance in practice – how oil affects servo valves and pumps
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Hydraulic system maintenance in practice – how oil affects servo valves and pumps

19/09/2025
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Source of information: ExxonMobil

As the end of the year approaches, factories face intense pressure to meet production plans, with every hour of machine operation becoming more valuable than a tonne of steel. Production managers know that finding additional productivity reserves is akin to walking on the edge of physics rather than routine resource management. Although hydraulic systems may initially appear to be ‘simply’ efficient, they are in fact the beating heart of the plant, determining the rhythm, stability and predictability of the entire process.

Mobil™ specialists have revealed that companies often underestimate the important role played by hydraulic systems. This issue cannot be ignored in a world of tight margins and fierce competition. Invisible drops in performance resulting from the use of lower-quality oils can quietly erode a company’s financial foundations, increasing the risk of downtime and uncontrolled service costs.

Conversely, investing in high-quality hydraulic oils is not merely cosmetic, but a genuine means of achieving stability and gaining a competitive edge. The reserve of efficiency lies precisely in a precisely selected lubricant, rather than in expensive modernisations or desperate increases in the pace of work.

The role of preventive maintenance of hydraulic systems

In the industrial world, precision and reliability are not luxuries, but conditions for survival. This is why maintenance of hydraulic systems, which is often overlooked in the daily production cycle, is a vital part of a preventive strategy. If you compare a hydraulic system to a heart, oil is its blood. This is no exaggeration, as it is the quality of the oil that determines whether machines can operate continuously and avoid costly downtime.

Hydraulic oil has a tough job: it must work under enormous pressure and high temperatures, and withstand contaminants, all while maintaining its properties during long periods of continuous operation. Paradoxically, despite playing a strategic role, it accounts for less than 1% of total maintenance costs. This figure should make every production engineer sit up and take notice – investing in high-quality oils is not an expense, but an insurance policy for the heart of the plant.

Higher efficiency of hydraulic systems

In practice, the degradation of hydraulic oils is the result of a complex interaction between high temperatures, pressure, and reaction catalysts such as metals from working surfaces.

This results in the formation of oxidation products that accumulate as deposits and varnish on valves, piston guides and in lubrication channels. This directly translates into decreased control precision and an increased risk of failure of pumps and servo valves with very small clearances.

Mobil DTE™ 20 Ultra oils have been developed to inhibit this process. Their high thermal stability limits the formation of free radicals that are responsible for degradation. Their unique detergent-dispersant formulation keeps microscopic particles in suspension, preventing them from agglomerating and depositing in critical points of the system.

The effectiveness of this mechanism is verified by Mobil Hydraulic Fluid Durability (MHFD) tests, in which Mobil DTE 25 Ultra achieved a cycle life of 2,000 hours, almost double that of standard ISO VG 46 oils with zinc additives (ZnDTP).

In practice, for CNC machines or precision hydraulics, this translates to clean oil channels, fully mobile servo control elements, and stable damping characteristics, even during long production cycles.

In terms of hydraulic system maintenance, this not only means less frequent oil changes, but also extends the service life of pumps and valves operating under extreme loads.

This is confirmed by approvals from over 650 original equipment manufacturer (OEM) partners, demonstrating that oil acts as an active element in machine reliability strategies rather than merely as a working medium.