After taking all of these precautions, Southworth-Milton takes more steps. “We also use the Cat hose-cleaner group for hoses and tubes, which shoots foam rubber projectiles sized to fit hoses of various sizes through the tubes. At least three projectiles are shot through the new hoses to make sure they’ve been cleaned correctly. We use this tool in the parts department for newly built hoses, in the service shop, and in our field-service trucks, which are used for repairs to hydraulic systems.”Once the components are sufficiently cleaned, Southworth-Milton workers turn their attention to the hydraulic oil itself. “Our 90-gallons-per-minute filter carts, which contain a bank of four or eight 10-micron filters, filter oil in the machine while we’re working on it. We call it a ‘kidney machine’ because it’s like a dialysis machine for oil. We measure readings on the hydraulic fluid with a portable particle counter; after measuring the contaminants, we clean the oil up to Caterpillar’s cleanliness standards of ISO 18/15. This saves the customer the expense of replacing fluid.”Much care is taken to protect stored liquids from contamination. “We also have filters on all of our bulk oil-storage tanks, both hydraulic oil and transmission oil,” Leary says. “The oil is filtered to the 10-micron level not only for the service shop but also for the trucks that go out to the field to perform preventative maintenance on our customers’ machines. As an added precaution, the lube trucks also have 10-micron filters on their discharge lines, and this is monitored on a monthly basis to ensure that the oil being put into customers’ machines meets Caterpillar’s ISO 16/13 spec.“We also monitor oil conditions in our customers machines and engines to be sure they meet Caterpillar standards,” he goes on. “We partner with another Cat dealer in Pennsylvania on an oil-analysis lab. We use our portable particle counters for shop work when immediate results are needed.“We haven’t found water to be a significant contamination problem with our oil-storage systems, but we do check fluids for water content,” Leary says. “All bulk oil containers have 2-micron filters as breathers. On some of our larger tanks, we use a dessicant breather. Our lube trucks are enclosed, insulated, and heated so tanks, pumps, and reels are kept clean and oil pumps easier.”Southworth-Milton’s dedication to cleanliness also has been preached to its customers. “We do customer training on contamination control; it’s important that our customers know the importance of contamination control and follow the same standards as we do in our shops,” Leary concludes. “They have to be aware, when they open the system up, that they are opening it to airborne dirt. Also any other containers they may be using to pour oil could be contaminated; they should use the original can and hopefully use a pump and filter arrangement when adding oil.”Clean Softly, but Carry a Big Filter“Good manufacturers adhere to good manufacturing processes, and this includes delivering clean products. We clean our hydraulic components, subassemblies, and systems during the final steps of manufacturing,” says Ed Blackford, Eaton Hydraulics’ manager of proactive maintenance and filtration. “We use oil that has been filtered to specifications that exceed customer requirements. There was a time when manufacturers sometimes produced and delivered items that were less clean than the system required. The user was expected to clean up the system at startup. Now the burden has shifted to the manufacturers. Good manufacturers produce, package, and certify hydraulic products to a cleanliness code. Customers should verify that the manufacturer adheres to a cleanliness code requirement when evaluating suppliers.”Those tiny contaminants must be filtered out using the cleanest oil possible. “If there were other particulates in the oil, that would make matters worse,” Blackford says. “The intense pressure inside a hydraulic system can turn small particulates into big problems. As a comparison, the typical home has water pressure of about 40 to 50 pounds per square inch. Many hydraulic systems run pressure of 3,000 to 6,000 pounds per square inch. At this pressure, a small particle coursing through the system will abrade, or ‘sand,’ the surface inside the system, breaking down into more particulates and creating more problems.” As is the case with other engines or vehicles, new hydraulic systems require a break-in period; overstressing the system during this time could cause damage. “It’s much like when you get a new car and you’re supposed to drive it gingerly the first 500 miles,” Blackford explains. “If anything like metal filings would shed off the new engine components, the oil system would filter them out.” Although hydraulic systems are secure and closed most of the time, contaminants still can get inside from outside sources. “While many operators believe the system is closed, operators do open the hydraulic systems to the atmosphere – for example, when changing a part, or when adding oil – and this is when many contaminants enter the system.” Most systems are continuously exposed to the atmosphere through a reservoir breather. These systems are designed to draw and return oil from and to a reservoir. The reservoir would implode if it didn’t have a vent to the atmosphere, but through this vent contamination can enter the system. “Common forms of contamination include dust and moisture. Most people in our industry use breathers or vents that are little more than mesh screens. These screens keep out large items like screwdrivers or rags but do nothing to block dust and moisture. If a customer looks at oil and thinks it looks clean, looks can be deceiving. The human eye can only see objects as small as about 40 microns, but most oil contaminants are about 5 microns. The reality is that we can’t see most of the things that will damage hydraulic systems.”Is there a solution to this problem? “More than 90% of hydraulic system failures are preventable. These problems could be remedied with adequate filtration,” Blackford states. “Some filters will reduce the number of particles in oil. Others can reduce the number of particles and take out water. The ones that take out water work like GORE-TEX fabric raincoats; they let air breathe in and out, but the water stays on the outside.”Eaton Corporation developed new filter technology and packaged in a reservoir breather product called the H2O-Gate. The H2O-Gate vent breather prevents water vapor from entering the oil reservoir while permitting air to escape, which lowers the relative humidity inside the reservoir and significantly reduces condensation.Designed to withstand the most rugged hydraulic environments, the lightweight H2O-Gate is effective down to 40°F, and it’s easily installed; it only needs to be hand-tightened onto an adapter. The internal media surface incorporates a layer of oil attractant, which coalesces any oil splashes and drains them back to the reservoir. Proprietary media within the filter not only reduce dew-point temperature, but they’re also 99.7% efficient in blocking particles 3 microns and larger.Blackford suggests that, whenever possible, operators should use gauges or indicators to signal when it’s time to change the filter. “Every operator should have a proactive maintenance program, a plan to prevent problems before they start, because, when systems fail, it costs you money. It costs more to fix a problem than to prevent it,” he says.Avoiding Wear – There’s the RubAnother way to prevent problems is by avoiding damage and wear. “On earthmoving equipment, some hydraulic hoses are on the outside of the machine,” notes Bill Dorton, vice president of sales and marketing of South Bend, IN’s Clean Seal Inc. “We make hose-protection systems to prevent abrasion, to keep hoses from rubbing together. Lots of times, hoses rub against metal, which eventually wears a hole in the hose; once the hose has gotten bad, you can’t really fix it. We have a system that protects hoses – a sleeve made of 66 nylon that goes over the hose.”In many cases, only a small portion of the hose will be vulnerable to wear. “Sometimes you’re trying only to prevent wear in an area about an inch long. Our hose protectors can be attached with nylon ties in the areas that need it most. We also offer spacers and looms, which keep hoses of the same size away from each other, locked down, keeping them from touching and wearing,” Dorton adds.Oil’s Well That Ends WellDespite the best-laid conscientious prevention plans, there’s still a chance that something might go wrong. Are there diagnostic tools or procedures that can point out potential problems? BP-Castrol Off-Road Marketing Manager Jim Burke suggests his company’s computerized oil-analysis services.“Take a hydraulic oil sample, send it to us, and we will analyze it,” Burke says. “We need to know the make and model of the unit and the amount of hours on that oil. We will measure the parts per million of metallic substances, from which data we can tell you where the system might be moving toward catastrophic failure. Particle counting is the key to sampling. Our lab counts particles of different sizes; learning that data is a better way to find out where wear is taking place.”Castrol’s computerized oil analysis doesn’t work on a one-time-only basis; a series of samples must be taken over a period of months to establish the machine’s baseline readings. “Just as when your blood shows high bad-cholesterol levels, your doctor will warn you of the possibility of a heart attack, high levels of a certain substance in your hydraulic oil can point to a problem. Let’s say we find elevated levels of copper over previous tests,” Burke explains. “Only a few items inside a hydraulic system use copper in their construction, so we’d tell you that you should check on those items. It’s certainly easier to tear down the pump, for example, and find out what’s going on rather than tear the entire system down.” Can this testing have an impact on oil changes and other maintenance? “We always recommend seeking to meet the machine’s manufacturer’s recommended drain schedules, but with our oil analysis, maybe you can extend that schedule,” Burke says. “You might say to your equipment dealer, ‘Can I go 750 hours between oil drains and not invalidate my warranty? I’m using Castrol’s samples.’ In some cases, the manufacturer might let you work with them on warranty guidelines if you send them Castrol’s reports.”Machine owners who are already Castrol customers need only ask their rep about how to have computerized oil-analysis services done on their machines. Others interested in the program can get more information at www.castrolhdl.com, or by phoning 800/777-1466 and then following the voice prompts.“Of course, we hope you’re using Castrol Blue Hydraulic Plus oil, which is dyed blue for leak detection,” Burke notes. “But anyone can purchase our computerized oil analysis, no matter what oil they use.”
