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.
- Contaminant ingress.
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 a fluid 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
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.
- equipment required to empty sumps and drip trays, and degrease machine surfaces; and
- consumables such as detergents and absorbent material.
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.
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
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.
"This book has the potential to save many
organizations lots of m0ney. It should be on the bookshelf of every engineer, supervisor, planner and
technician that deals with hydraulic equipment... it's worth its weight in gold." Find out more
Alexander (Sandy) Dunn
Plant Maintenance Resource Center