Trucking's Dirty Little Secret
Keeping Fuel Clean
That can be easier said than done, depending on how much control you have over vehicle refueling and whether it's on-site or at gas stations and truckstops.
Jim Winsor
Executive Editor
Fleets can save themselves a lot of trouble and expense by making sure that diesel injectors receive clean, water-free fuel. This may be easier said than done, depending on how much control you have over vehicle refueling, and whether it's on-site or at gas stations and truckstops. The type of fuel filter used and its micron rating also has a major bearing on fuel cleanliness.
If your fleet has its own fuel storage tanks and buys by tank-truck loads, make sure you know what's being delivered and check it. Some fleets take fuel samples at the time fuel is dropped, marking the brand, delivering carrier, time and date. These samples are stored for at least three delivery cycles and regularly checked to see if any water has settled to the bottom of the bottles, or if the fuel itself is discolored or cloudy. If fuel is suspicious, it is sent to a lab for analysis and appropriate action is taken against the fuel provider and/or the delivering trucker.
The next step is to make sure fuel island dispensing pumps each have functioning fuel filters - the lower micron rating the better without affecting the pumps' delivery rates. Make sure these filters are changed at regular intervals. Stick in-ground storage tanks with water-detecting paste or make sure your delivering trucker does. This procedure will give a "heads-up" to any in-tank contamination. And if any is found, have it chemically treated and/or pumped.
When are your vehicles fueled? Ideally, it should be at the end of day or run because today's diesel engines - depending on make - recirculate as much as 90% of the fuel delivered to the engine. Each "trip" to the engine and back increases fuel temperature, and sources tell HDT that in-tank fuel can reach well over 100 degrees F. Hot fuel in a mostly empty tank leaves hot air, which cools and condenses, forming water droplets that are added to the fuel. Refueling before parking for the night or weekend is desirable.
Today's truck fuel tanks, with few exceptions, no longer have sumps. Sumps are the low point in the tank where dirt and water collect. Sumps made it easier to drain off contaminants during preventive maintenance (PM) servicing. Even without sumps, more and more fleets tell HDT that loosening the tank plug and draining off a small amount of fuel is a smart procedure.
A trick some fleets use is to park vehicles on a slight slope overnight or weekends. Any water or dirt will tend to settle to the low point in the tank where it can be drained off. Roadway Express' late vice president of maintenance Don Dawson, even went to the trouble of having tractor fuel tanks mounted with a 3-degree pitch to the rear. Water and dirt would settle there and could easily be drained off. It was one of dozens of "Dawsonisms" he invented to reduce maintenance needs and costs.
If your fleet doesn't have on-site fueling and must rely on local service stations or on-road truckstops, it's even more important to check for water/dirt in the fuel. Ask your drivers to report any fueling locations that don't have in-hose filters at their fuel islands. HDT has learned there are occasions where fueling personnel - with and without management approval - have removed filters because they'd detected a slowdown in pumping rate. Rather than replace a partially-plugged filter, they remove it to get vehicles through service islands faster.
One fleet manager we interviewed found that his own personnel were removing filters to speed up the evening refueling rush when trucks came in. When drivers do their own refueling, they should report any "slow" pumps so filters can be replaced - not removed.
Maintenance managers should review PM procedures to make sure fuel tanks and fuel filters are serviced regularly. Darry Stuart, who has managed many fleet maintenance operations over the past 30 years, says a fleet's PM program should be designed so vehicles can make it from one PM service to the next without road calls or returning to the shop. When it comes to water in fuel, he says he is still a firm believer of adding a pint or more of isopropyl alcohol (rubbing alcohol) to truck fuel tanks at each PM service and more frequently during extremely cold temperatures where fuel line freeze-ups may be a problem. Alcohol absorbs water.
Stuart now has his own business advising fleets with hands-on management leadership.
He says that while there are a number of good fuel additives on the market, most of them are alcohol-based and more expensive than buying cases of isopropyl alcohol at the local drugstore. "I have never had problems with it affecting seals or O-rings, and it quickly absorbs water, emulsifying it into the fuel and carrying it to the fuel filter which, hopefully, will contain it and eliminate ice crystals from forming on filter media during sub-freezing temperatures.
"I've seen actual cases where tractors with 200-gallon fuel tanks would arrive back in New England in the winter loaded with water. I thought it was bad fuel. I discovered the hard way that some of these rigs fueled over 1,000 miles away, and by the time they reached Massachusetts, the remaining fuel in their tanks had climbed to over 100 degrees. With ambient temperatures in the teens, these tanks were sweating the way a glass of ice water does on a summer day. We drained up to two quarts of water out of these tanks at times. That convinced me that we really needed to trap water before water-laden fuel hit the injectors.
"It used to be that standard OE fuel filters were adequate, but as injection pressures have gone up, and the price of injectors with it, anything but the cleanest and driest fuel is risky. I personally don't think 12 - 15 micron filters are enough. About three years ago I started adding secondary fuel filters with water separators and heaters. I'm now shooting for 3 - 5 micron filtration in my specs.
"Did you know a human hair averages about 40 microns in diameter? Injector orifices today are a lot smaller than that. What we did with our old mechanical injection systems won't fly today. Consider that 2 microns is 200 times smaller than 5 microns. You can't even see two microns.
By the time the 2007 diesels get here, we may be dealing with this kind of stuff. It's already worrisome just thinking about that. The question is, are we reaching the point that today's fuel, as we receive it, may have to be re-refined to a higher level on the vehicle?"
At Dunbar Armored, a national armored truck service headquartered in Hunt Valley, Md., Director of Fleet Maintenance Doug White is making changes in his PM program. He's changed fuel filtration specs as a result of increasing downtime and failed injectors.
Dunbar Armored operates in nearly every state. Many operations have less than a dozen vehicles, making it cost prohibitive to have central shops. White relies on outside vendors and truck dealers, and he uses in-house shops and mechanics for his bigger operations.
Adding to his problems is the fact that almost all fueling is done at in-city "mom and pop" service stations - often a different one every day as armored car routes vary daily. He has little control over fueling practices. In the armored car business, security is the No. 1 priority and drivers are told to get in and out of fueling stops as quickly as possible.
Almost all of Dunbar's trucks are Class 6 or 7 with the International DT-466 and 530 the predominant engines. It wasn't until he surveyed all his locations and had fuel tank sampling done that White found out many, if not most, truck tanks had accumulated water. And fuel filters were not always being drained or changed because of their awkward location under the firewall. They were hard to get to, and mechanics often got a diesel bath when changing them.
White also surveyed injector replacements to learn how many were high-engine-hour replacements (armored cars never shut off) and how many weren't. He put his supervisors on alert to collect bad or failed injectors. That's how he discovered he had a problem that he thinks may be water-related. He currently has experts analyzing several injectors to get an independent and impartial answer. He thinks some blown injector tips may be caused by water in the fuel.
In the meantime, White has directed that all fuel tanks be drained of all accumulated water at each truck's PM service. He also is looking for an alternative OE fuel filter because the present one "isn't doing the job." And to make life easier for all service personnel, he plans to spec fuel filter locations on a frame rail where they're visible, easier to get at and at a level where mechanics won't get a diesel shower when they change them.
In July, he started installing the new WEBB VorMax fuel filter, which uses cyclonic action to spin out up to 97% of water and solids. That's before fuel reaches the standard OEM spin-on filter element, which is built into the VorMax mounting manifold. In addition, it has a built-in filter restriction gauge that shows when the filter element needs changing because of pressure drop.
This eliminates many premature filter changes. A translucent collection bowl with a drain is built into the base of the water separator to show the amount of accumulated water and contaminant removed from the fuel before it passes on to the spin-on filter element.
White is initially installing a dozen of these VorMax units in trucks located in different parts of the country. He wants to get regional feedback as to how bad his fuel situation is.
White reported that with the first two units, the bowls had nearly filled with water within two weeks.
"I'm learning a lot in a hurry," he said. "If the failed injector analysis tells me that watered fuel is my main problem, I think I can get that under control.
"I just hope a lot of damage hasn't set in already."
Sidebar
Finer Filtration: Is It The Answer?
Related Article
Trucking's Dirty Little Secret
