The true cost of hydraulic oil leaks

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Hydraulic systems are often considered perennial consumers of oil and in turn, make-up fluid an inherent cost of operating hydraulic equipment. But what is the real cost of one or more "minor leaks" on your hydraulic equipment? To answer this question, the costs associated with all of the following factors need to be considered:

  • Make-up fluid.
  • Clean-up.
  • Disposal.
  • Contaminant ingress.
  • Safety.

Make-up fluid

The cost of make-up fluid should be the most obvious cost of hydraulic system leaks. I say 'should be' because many hydraulic equipment users fail to consider the accumulative effect on the cost of one or more slow leaks over time.

Consider a leak from a hydraulic fitting that produces six drops of oil per minute. Hardly worth your attention, right? If the volume of each drop was half a milliliter, over 24 hours the loss is nearly half a liter - perhaps not a significant amount. But over a month this equates to 15 liters and 180 liters over the course of a year. Assuming an oil cost of $2 per liter, this "minor leak" is costing $360 per annum in make-up fluid alone.


Where there are oil leaks there is almost always a clean-up cost to consider. Clean-up costs include:

  • labor;
  • equipment required to empty sumps and drip trays, and degrease machine surfaces; and
  • consumables such as detergents and absorbent material.

Assuming it costs $10 per week in labor, equipment and consumables to clean up the minor leak discussed above, the annual clean-up bill totals more than $500.


I can remember a time, not so long ago, when waste oil companies used to pay for the privilege of emptying waste hydraulic oil tanks. These days they bill you for the privilege. Environmentally acceptable disposal of waste oil and absorbent material containing waste oil costs money.

Assuming a disposal cost of $0.60 per liter, the annual disposal costs attributable to the minor leak discussed above amounts to $110.

Contaminant ingress

Where oil leaks out, contaminants such as air, particles and water can get in. Costs to consider here include:


In many situations, oil leaks can pose a safety hazard. Like the costs associated with contaminant ingress, the costs associated with the safety risk posed by oil leaks are difficult to quantify - short of a lost time accident actually occurring. In addition, the cost of minimizing the safety risk can be obscured. An example would be more frequent clean-up than may otherwise be required. This hides what is essentially a safety cost in clean-up expenses.


The annual cost of one slow leak, similar to that discussed above, amounts to nearly $1,000 per year in make-up fluid, clean-up and disposal costs alone. If you have multiple pieces of hydraulic equipment with several leaks on each one, the accumulative cost over an extended period of time should alarm you. Inspect your hydraulic equipment today and tag all leaks for corrective action during the next available maintenance outage. It could save you a lot of money!

Related articles:

Why you should record all hydraulic oil top-offs
Pressure intensification in hydraulic cylinders
How to nail hydraulic logic element leakage

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