In your last hydraulics bulletin, I wrote about what I consider to be THE most important component of every hydraulic system – the oil, and the importance of taking care of it.

One of these is to control contamination. Studies have shown that it costs 10 times more to extract contaminants from hydraulic fluid than it does to exclude them in the first place.

Three common points of contaminant ingression are:

1. Reservoir breather.

Standard filler-cap breathers fitted to the majority of hydraulic reservoirs are not effective in preventing the ingression of airborne contaminants. All air entering the reservoir should be adequately filtered. In damp environments (e.g. marine applications, tropical climates) desiccant breathers are essential to prevent the ingression of airborne moisture.

2. Cylinders.

Worn or damaged rod-wiper seals and pitted or gouged cylinder rods give dust and other contaminants an easy path into the system. Fitting rod protectors (bellows) to cylinders operating in abrasive or corrosive environments can extend rod and wiper seal life and provide an extra barrier to the ingression of contaminants via the cylinder rod.

3. Plumbing.

Where fluid leaks out, contamination can get in. The immediate rectification of hydraulic system leaks not only minimizes the cost of clean-up, disposal and replacement fluid, it also saves the hidden cost of removing ingested contaminants.

Yours for better hydraulics knowledge,

Brendan Casey
Author of Insider Secrets to Hydraulics