Fleet Management Information for Sweeping Professionals

Isuzu Responds to Reported Fuel System Issues

In the early months of 2014 the World Sweeper office received a number of reports from parking lot sweeping contractors concerning trouble they were having with the fuel systems on their Isuzu chassis. These seemed to especially concern the 2006 and 2007 model years.

Initial speculation centered around the idea that the reported issues could be the result of the 2008 model year changes, by Isuzu and other manufacturers, that were mandated by the federal government. For the 2008 calendar year, Isuzu and other manufacturers were required to modify their chassis to include diesel particulate filter (DPF) systems. At the same time, diesel fuel went to an ultra low sulfur content. The problem with the latter is that sulfur acts as a lubricant in the fuel system. When the sulfur content went down, so did the lubrication ability of the fuel. That, in and of itself, is cited as a potential cause of more fuel system problems.

We also know, anecdotally, that the sweeper manufacturers stocked up on chassis built in those model years, in order to have them available to customers who did not want to be among the first to use the 2008 models. Isuzu sources confirmed that sales in the 2006 and 2007 model years were extremely brisk, likely for that reason. However, once purchased by companies (like sweeper manufacturers) who were upfitting their product types onto these chassis, many of the purchased chassis sat unused for up to three years. This may have contributed to fuel system issues, as well.

We contacted Isuzu and provided the company representatives with our collected information. In this article we are providing the response from two top members of the U.S. Isuzu management team. James Barnes, one of Isuzu's regional managers who has long worked with sweeper manufacturers, Victory Sweepers, Inc. and Schwarze Industries, Inc., coordinated the interview we held with him and Mike Rossetti, Isuzu Commercial Truck's Director of Field Operations.

This article also includes the approximately 26-minute audio interview held with both men. In the audio, the issue is discussed at length and various ideas are put forward to minimize problems with the Isuzu fuel system, as well as discussing ways to maximize the system's longevity.

Here's what Mike Rossetti said as an introduction to the situation. BTW, he made it clear that these circumstances were faced not just by Isuzu, but by chassis manufacturers nationwide: "The government changed the fuel to ultra low sulfur fuel. The sulfur kind of acts like a lubricant, but by going to the ultra low sulfur fuel the lubricity is diminished greatly. Then, when moisture gets trapped in the fuel systems, mixing with the ultra low sulfur fuel, the acidic level of the fuel starts to climb dramatically.

"Not just truck manufacturers and automotive manufacturers, but even the refineries started to experience these high acidic values in certain areas, like places where there was high temperature and/or high moisture. Even the refineries were experiencing rust in their tanks from this issue."

When asked what specific steps owners of these chassis might take to avoid or reduce fuel system problems, Rossetti offered that there are many fuel system treatments on the market that claim to increase lubricity as well as to provide other benefits to the current diesel fuel that has the very low sulfur content. However, not knowing the details of these, he chose not to recommend any specific product that might be used in this regard.

Rossetti did offer the following tips, though: "When you're purchasing your fuel, be sure to purchase from a brand name company or from a facility where you know the fuel is a top grade product. Monitoring of your fuel filters is equally important. When you do replace fuel filters be sure to replace with a quality filter. Isuzu filters are efficient down to 5-microns, as are some others on the market. However, there are also some filters out there that are not as good as OEM. Having good fuel and quality filters reduces the likelihood of having fuel system issues. This is not so much related to potential rust in the tank, but rather are items that give the injectors a longer life."

There is also a definite value, Rossetti went on to explain, in keeping the fuel tank as full as possible. This makes it harder for rust to form, which is easier to take place on the exposed parts of the inner surface of the fuel tank. Although Rossetti mentioned that he has heard good things about a variety of fuel injector cleaning products, he again declined to recommend any specific brand by name. However, he agreed that anecdotally it appeared that periodic use of a good fuel injector cleaner might make sense to do as a preventive.

On the issue of fuel filters, Rossetti reminded that any filter will only last a particular length of time given the conditions under which it is operated. For example, if you put a new fuel filter into a vehicle with rust or other particulate issues, it can plug quite quickly. That's where an accurate record-keeping procedure on each truck can pay dividends. By keeping tabs on the typical fuel (and other) filter changeout intervals, the owner can schedule maintenance that includes filter replacement before a clog occurs that mandates a service call or a tow. In the case of fuel filters, many of which are easy to replace with a minimum amount of tools, it might make sense to carry a replacement in each vehicle.

"If a fuel system gets contaminated," said Rossetti, "it can plug up in as few as a hundred miles. There's really no mileage interval that fits across all situations. It depends upon the usage conditions. If you replace your fuel filters on a regular basis, though, prior to when you'd normally expect they'd reach their end of service life, you have less chance to have troubles on the road."

One tip for making sure your diesel fuel is not particulate-filled when you purchase it at the pump is to make sure not to fuel up while a tanker truck is off-loading into the same storage tank you're drawing from. If there's a tanker onsite when you are at a station getting fuel, you might go ask the operator which tank is being filled. If it's the diesel tank, you chance filling up with fuel that has more particulates than normal, since the fuel is being 'stirred up' by the tanker truck's fueling process.

Rossetti said that vehicle speed or usage doesn't have any bearing on fuel system longevity. For example, a sweeper that goes at low speeds much of the time doesn't have any stronger possibility of fuel issues than a delivery truck or over-the-road hauler. However, he did remind that if you lose the truck's fuel cap, make sure to replace it immediately. Running with a rag in the tank filler neck provides the potential for moisture to wick into the fuel tank. Ditto for making sure your fuel tank cap is clean and is making a good seal.

"In some models, the filler neck and vent are located near where the mudflaps are," continued Rossetti. "In those cases, dirt and mud can cake up around the filler neck. Be sure to keep the area surrounding the filler neck clean and free of this type of material that might fall into the fuel tank when you take the cap off. Dirt caked onto the vent valve also, in essence, forces dirt and contaminants into the fuel tank. Both of these can start the rust process happening.

"Keep in mind that if you go look at your vent valve area and find it's covered with grease and road grime, chances are, some of it has already gotten into the fuel tank. If your vent valve and filler are, for some reason, located where a lot of dirt and grease are collecting, look to see if you can relocate it to a different spot where that won't keep re-occurring."

When you do think there might be a problem with where the fuel filler, vent valve or any other chassis component is located on your sweeper, be sure to discuss any changes with your Isuzu dealer and/or sweeper manufacturer. Remember that the sweeping application is one of the most challenging vehicle applications there are, due to the slow speeds, large amounts of dust and more. If you are having issues with any of the chassis (or sweeper) systems, make sure to contact the appropriate personnel at the chassis or sweeper dealership. The earlier you can identify a problem and get professional consultation on it, the better chance that any negative effects can be minimized.

When asked if pressure washing or otherwise cleaning the engine might have a positive value, Rossetti responded that it's always better to keep an engine clean. Dirt on engines traps in heat, for example, as well as can mask the early signs of other problems like leaking hoses. Remember, he reminded, that engines that run cooler also run longer. However, he also cautioned about putting a hard pressure spray onto any sensitive engine components.

While I had him on the line, I asked Rossetti if there were any steps that could be taken to increase the longevity of transmissions. I started the conversation by recalling that a California contractor with a large fleet had once told me about a significant cost savings he had realized by adding a GPS marker onto his transmission circuit. The marker notified the system whenever the vehicle gear was changed from forward to reverse – and vice versa – while the vehicle was still in motion. The contractor added the GPS marker because he was going through lots of transmissions. Adding the GPS marker, he had told me, saved him an average of $2000/month over his entire fleet.

Rossetti did have a constructive suggestion to make. Because of the large dust factor with sweeping, he said it is critically important to make sure that the rubber seal on the top of the transmission dipstick stays intact and that the dipstick isn't allowed to 'ride up' on the channel, exposing an area where dust and dirt can get down into the transmission fluid reservoir. Water could also get into the tube when the engine is cleaned, which would be equally hard on the system.

Whenever the transmission fluid level is checked, be sure no dirt can enter from the surrounding area, that the dipstick seal is intact, and that the dipstick is fully re-inserted back into the check tube. Rossetti said he did not recommend the use of any additives for the transmission. Also, he said, there is a transmission cooler already in place on Isuzu chassis. Just be sure to do the above and then replace the transmission fluid every 30,000 miles or, on other chassis, according to manufacturers' recommendations.

He also said that a trained service tech can see and smell the telltale signs of worn-out or compromised transmission fluid. When the fluid has an 'electrical burning' smell is one of the signs that the fluid has been running hot, he said, as is a darkening of the fluid. However, it takes a trained professional to make those types of judgement calls.

In the accompanying 26-minute audio interview you will find the above information discussed in greater detail than what you have just read. However, all of the major points have been included in the written article. If you have questions or comments on these or other topics, we encourage you to let us know. If appropriate, they will be added as an addendum to this article.

If your organization has had similar issues with either the older (pre-2008) or newer Isuzu chassis, be sure to let us know so we can add your info to our documentation.

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