The Case for Fluid Analysis

Laboratory analysis of fluids such as engine oil, fuel, coolant and hydraulic fluid, can be a very powerful tool—provided you know how to use it.

According to Diego Navarro, service marketing manager with John Deere Construction and Forestry Division, the benefits of sending oil samples for testing are numerous. Analysis can detect machine wear, aging of the oil and even whether you're using the correct fluid. It can also detect the presence of mixed fluids, which can be very dangerous.

Another function of oil analysis is to help fleet managers understand the work environment of the machine.

"If a machine works in water, you'll see more humidity," says Navarro. "If it works in Florida, you'll see sodium in the sample. If the machine is working a jobsite in Illinois, you'll find aluminum."

Oil analysis can also recognize if maintenance is adequate.

Mark Minges, COO for Polaris Laboratories, says oil analysis gives fleet managers advanced notice of pending failure.

"It allows you to schedule maintenance and avoid unscheduled downtime," he says.

Testing oil samples can also identify contamination and the possible sources for it, as well as providing other information that is vital to equipment management.

When analyzing coolants, says Minges, you also monitor for adequate metal protection and prepare for extreme temperature variations.

"It ensures the fleet is ready for winter and summer," he says.

Fuel analysis has three major benefits. It monitors:

• Contamination, such as bacteria, fungi and mold, which can plug fuel filters and significantly shorten fuel filter life
• Ignition quality. For instance, the Cetane index, distillation and flash point determine how efficient the combustion process is, and whether or not it's able to provide sufficient power to the engine
• Lubricity.

"The EPA now requires the use of ultra-low-sulfur diesel fuel (ULSD), but the refining process for low-sulfur fuel can reduce lubricity, which is the oil's ability to lubricate fuel injections," says Minges. "By measuring lubricity, you can determine how much lubricity agent needs to be added. But before you add anything to the oil, you should discuss it with your oil supplier."

Fleet professionals are becoming increasingly aware of the benefits of oil and fuel cleanliness.

"We're seeing more interest in fluid cleanliness, wear debris analysis and varnish detection," says Minges. "People are starting to understand contamination and its effects on equipment performance. They are also realizing the value of doing analytical ferrography or micropatch testing in conjunction with ICP. Since ICP only detects particles of a certain size, ferrography will identify larger particles, as well as help determine the possible sources."

Another sign fleet managers are beginning to associate fluid cleanliness with good equipment performance is evident in the significant increase in requests for particle counts on fuels.

Requests for biodiesel testing are also becoming more common.

"Because there are no manufacturing standards for biodiesel, fleet managers should always test to determine product quality," says Minges. "Testing for ignition quality should include measuring glycerin content; the presence of bacteria, fungi, mold and water; and cold-weather properties."

Deere's Navarro says biodiesel testing provides different results.

"We're going to start seeing different things now, such as metals we didn't see before," he says. "We may see fuel dilution, more rust and even changes in emissions because the use of biodiesel increases nitrous oxide."

Part of the issue is the way biodiesel is processed.

"Biodiesel is part acid and tends to be more corrosive toward metal," says Navarro "That's why we see more tin, lead and copper. Biodiesel also catches more water. It's heavier than diesel fuel and tends to stay in suspension in the oil for longer periods of time. It's very difficult to evaporate, so it has more time to react with the oil and cause damage."

Although biodiesel mixes well, it can be difficult in cold weather.

"Biodiesel doesn't flow easily when it's cold, so it clogs filters," says Navarro. "And when biodiesel isn't processed correctly, glycines aren't removed. That forms gels that clog filters. There's a process to remove the crystals, but it's expensive."

To combat the effects of the many of the recent engine changes necessary for emissions compliance, new oils have been formulated for use with ULSD.

"ULSD is a great addition," says Navarro. "It can help the oil survive much longer. In the past, oil changes were determined by the amount of sulfur in the fuel. Today, the manufacturer might recommend you change the oil every 500 hours, but that's only a suggestion. You could have consumed your TBN in half the time, maybe at 250 hours."

ULSD is designed to protect the components that are there to reduce air pollution, such as EGR valves and variable geometry turbochargers.

"They also reduce the amount of pollutants in the exhaust zone," says Navarro. "By reducing the sulfur, you're removing the compound that is naturally found in fuel. Therefore, ULSD needs some anti-wear additives that return the fuel to the lubricity that is required."

EGR engines increase the amount of soot that must be suspended in the oil, and while the new CJ4 formulations are keeping up, they have a lower starting base number.

"That can require decreasing drain intervals," says Minges. "When switching to CJ4 oil, it's a good idea to test to make sure the same intervals apply."

Although fluid analysis has become a routine part of many fleet maintenance programs, Mark Stamp, Luber-Finer product manager recommends fleet owners who are venturing into it for the first time should follow these simple steps when taking a sample:

• Bring the equipment to operating temperature
• Obtain a sample, for instance, from the oil reservoir
• Complete the sample information form included with the sample kit
• Ship the sample to the laboratory.

The laboratory will perform a battery of tests on the sample based on the component type.

During oil analysis, tests detect wear metals, such as sodium, iron, copper, potassium, sulfur, silicon and lead. When coolant samples are analyzed, tests detect total dissolved solids, freeze point, appearance, ph content and other factors. Fuel analysis tests for distillation, bottom water and sediment, pour point, flash point, color, and particulate matter, among other things.

After the analysis is complete, the lab will provide a written report indicating the component's condition.

"OEM threshold analysis has a set limit," says Stamp. "Trend analysis of equipment or an individual component shows spikes that exceed the norm. Statistical analysis is used when an engine manufacturer says one number is abnormal and fleet statistics show a different number as abnormal. With so many indicators, gauges, testing and analysis, fleet managers can be overwhelmed."

Once a fluid analysis program has been established, fleet managers can validate the effectiveness of the program by conducting monthly and yearly reviews.

"All it takes to start is to purchase kits and sample accessories," says Stamp. "Then establish the equipment database and an initial sample scheduling, and add or update as required. Next, review the samples in your active list and decide on corrective action from abnormal and severe sample reports. And finally, confirm maintenance was carried out and if it was sufficient to correct the problem. After all, the information is only useful if it's put to good use."

Lab analysis of fluid samples helps reduce equipment downtime, increasing productivity; decrease maintenance time and cost; and extend equipment life.

"Fluid analysis helps the fleet professional avoid catastrophic engine and component failure," says Stamp. "The end result is increased profits."