From Rolling Bearings Handbook and Troubleshooting Guide

After bearings operate for a period of time, they may develop deposits of lubricant varnish and contamination from the environment. Unused bearings may also become contaminated due to broken packages or dirty storage areas. In some instances, flushing the bearing with clean lubricant while it is in operation provides some cleaning.

When the bearings are very contaminated with dirt and sludge, soak them in kerosene, mineral spirits or special commercial solvents. Some solvents can be detrimental to nonmetallic cages, seals or other components. After cleaning with solvents, bearings are extremely vulnerable to corrosion or mechanical damage and should be protected or lubricated immediately. Handling with bare hands can corrode the bearing surfaces because of the acidic moisture on the hands. A clean, dry, unlubricated bearing can be easily damaged by the movement between rolling bearings and raceways. Such bearings should never be spun or subjected to shock or vibration before a coating of lubricant or preservative has been applied.

More about Rolling Bearings Handbook and Troubleshooting Guide

Operators and managers often overlook the critical role played by lube-oil reservoirs that support rotating machinery, hydraulics and mechanical power transmissions. Often viewed as lifeless metal tanks and sumps, half-hidden from sight and inaccessible, reservoirs not only are treasure chests of information, but they offer a convenient stage from which to perform remedial tasks.

Hard-working lube oils travel their circuits many times depending on the quantity of oil in the system. However, every drop of oil must return to the reservoir; the time it takes the oil to return depends on the system. A reservoir is like the Indy 500 grandstand; every unit of oil passes in front of it for review. But unlike race cars, that same drop of oil decelerates as it enters the reservoir, lingering while it waits its call to make another trip around the lube-oil circuit. Reservoir residency varies, yet while within the reservoir, lube oil is conveniently accessible to operators for analytical and remedial action. Read the entire article.

"Our plant has just upgraded all the breathers on our hydraulic systems to use high-efficiency hydraulic filters instead of the standard filler/breather caps. There seems to be no way to know when these filters need to be replaced. How can we change our air breathers based on the condition of the breather and prevent throwing away perfectly good filters?"

Condition-based maintenance is a great way to cut costs and to monitor the efficiency of specific components such as filters and air breathers.

The problem you are faced with can have catastrophic results if the change-out interval is longer than the useful life of the filter. Air filters on hydraulic systems are rarely included in regular maintenance inspections due to the impossible task of assessing the useful life left on a breather.

There are commercially available, inexpensive vacuum gauges that can be fitted to the adapter used to mount your hydraulic filter to your hydraulic reservoir. These vacuum gauges show you, how much service life has been used and even more importantly, how much life the element has left.

As the system draws air in through the filter, any restriction causing a vacuum will register a reading on the gauge. The graduated gauge is a telltale gauge that holds the highest reading in position until it is reset by pushing a button after replacement of the filter.

You maximize the life of the element, because the indicator allows you to change the filter when needed, thus avoiding unnecessary labor, downtime cost and replacement cost from under- or overservicing.

These gauges also provide the same opportunity for condition-based maintenance on diesel and gasoline engine air intake filters.

Jason Kopschinsky, Noria Corporation