Donaldson Co. is well known for clearing the air. Now, it’s trying to stretch its expertise into liquids, specifically diesel fuels.

The company is developing long-lasting fuel-filters for large trucks and farm, construction and mining vehicles.

It recently spent $3.5 million to renovate and create a state-of-the-art liquid laboratory in Bloomington. And last month, it launched a free fuel “Filter Forensics Service” to help truck, tractor and construction fleet owners learn why their fuel filters clog, a common headache for truckers.

“We’ll be taking customers’ clogged fuel filters and figuring out why it gummed up and had that trucker stalled on the side of the road,” Sheila Peyraud, the company’s chief technology officer, said in an interview.

Donaldson also introduced its new Select Fuel Filter and won $50 million in annual contracts from makers of “off road” construction vehicles and farm tractors and combines. It partnered with two state universities to study diesel fuels and launched a new website called MyCleanDiesel.

Over time, the fresh focus on fuel filtration is expected to add hundreds of millions to Donaldson’s sales, which amounted to $2.4 billion last year.

By entering the world of diesel and biodiesel filtration, Donaldson will compete with Fleetguard Cummins, Dahl-Baldwin Filters and Parker Hannifin Corp. Research firm MarketsAndMarkets recently estimated that the global fuel-filter market is growing and should reach $12 billion by 2018.

Donaldson started filtering fuel just four years ago. It began with filthy diesel storage-bins and pipelines. Two years ago, it started making “after market” fuel filters for older trucks already on the highway. Soon it will fulfill filter orders for new “off road” vehicles. Next Donaldson wants to supply fuel-filters directly to factories making new “on-road” trucks, Peyraud said. It already makes mufflers and other parts for truck manufacturers.

The new forensic service is “CSI for fuel filters,” said Chuck Christ, director of Donaldson’s liquid and mist filtration technology business. “There are more than 400 combinations of fuel additives in the newer diesel fuels,” he said. “So determining which combinations and at what temperatures are causing the clogging is a first step to identifying a solution.”

Trucking association leaders say that stricter biodiesel and low-sulfur-diesel fuel mandates created by Minnesota or the U.S. environmental agencies in 2008, 2010 and 2014 have successfully slashed smog and soot emissions. But they also say that some fuel mandates led to redesigned engines that needed extra time and technology to work out the kinks.

Without regular intervention, some truck engines clog with debris, mix water into the fuel or they stall because diesel and biodiesel tend to thicken in frigid temperatures, truckers have said at industry conferences and forums.

“Our customers experienced [all] these fuel problems and their additional costs,” said Dean Dally, co-owner of Blaine Brothers, a nine-location truck-repair business that helped hundreds of clogged trucks within the last year. Engine product makers have raced to create remedies such as fuel additives, sensors, fuel heaters and more recently high-tech fuel filters, Dally said.

Glen Kedzie, a spokesman for the American Trucking Associations, said that if Donaldson can add one more layer of protection against fuel filter clogs, then frustrated truckers will give them a try.

“We met with Donaldson earlier this year and they said this new technology would revolutionize the industry,” Kedzie said. “In reality, the ultimate deciders of this will be the truck fleets that will dabble with these filters to see if they perform as claimed, keep trucks out of the shop and out delivering products to customers.”

Donaldson’s revamped liquid-filtration laboratory, which opened three weeks ago, is equipped with the latest diagnostic and fuel-filter testing equipment, some of which is designed to test products in temperatures as low as -30 Fahrenheit.

On a recent workday, technician Neil Taurinskas injected highway dust the consistency of onion powder into a fuel filter. His colleague Steve Larsen then mixed corrosive water into diesel fuel and pumped the engine-killing blend through the Select Fuel filter. Other workers across the cavernous laboratory tested the new filters with varying vibrations, pressures and fuel viscosities. Computers charted each move as the filters screened out particles as tiny as bacteria.

“Our goal is to lead the market,” said Jon Seilkop, lab operations manager. “We are a leader in hydraulic filtration today and [soon] we will be a leader in fuel filters.”