By Diego Navarro
Aftermarket Sales Manager, Americas
John Deere
The old axiom that “changing oil is cheaper than buying parts” certainly applies to logging equipment maintenance, but changing oil is only one part of effective fluid maintenance.
Whether you’re talking engine oil or hydraulic fluid, it’s essential to follow the manufacturer’s specs for the individual systems on each piece of equipment. Buying one fluid in bulk because it’s “close” to what’s specified for several machines may seem like a good idea, but it can cause costly problems in the long run.
Similarly, it’s never a good idea to mix fluids in any system by “topping off” different systems with the same fluid. Mixing fluids can accelerate component wear and shorten machine life.
Fluid change intervals have long been based on hours of operation—a hydraulic fluid change every 2,000 to 3,000 hours, for example. But condition-based maintenance (CBM) can be a more time- and cost-efficient approach.
With CBM, a small sample is taken from each fluid system at frequent intervals (every 250 hours, for example) and sent to an independent lab for analysis. A CBM oil analysis:
—Measures the presence of contaminants. Dirt, water, fuel or coolant in the engine oil can indicate a leak or other problems. Water content must be monitored closely in hydraulics, especially in damp working conditions such as swamps.
—Helps determine the condition of the machine. Iron, copper or lead particles, for example, might indicate wear problems that can be addressed before they become expensive breakdowns.
—Measures “lubricant health,” including the oil’s remaining useful life. This is measured as the total base number (TBN) for engine oil. A typical TBN for fresh oil is 9 or 10 with current CJ-4 oils. When the TBN reaches 4 or 5, it’s time for a change. For hydraulic fluid, lubricant health is determined by the acid number. This number is typically around 0.5 for fresh fluid; it’s time to change at around 2.0.
Changing fluids on this basis ensures you’re getting the most value from every quart ofa oil you buy.
Filters
As with the fluids themselves, it’s essential to follow the manufacturers’ specs for filters and filter changes. Pay particular attention to each filter’s micron rating, which measures the minimum size of particles the filter can remove from the fluid, and its Beta ratio, which measures filtering efficiency. The higher the Beta ratio, the more efficient the filter.
In most cases, filters must be changed more frequently than the fluids themselves. Manufacturers typically recommend changing hydraulic filters every 1,000 to 2,000 hours (vs. 2,000 to 4,000 hours for fluids).
Follow each machine’s manual for filter change internal recommendations and pay attention to the contaminant measures in your CBM (condition-based maintenance) reports. Especially dirty or damp conditions make more frequent filter changes necessary.
It’s true, changing oil is cheaper than buying parts. But a consistent CBM program can save you even more. It can help you measure wear trends and establish a more efficient maintenance schedule to ensure maximum machine uptime and production at minimum cost per ton.