Salt is the weapon of choice for Iowa’s Dept. of Transportation. But the weapon used for keeping the roads safe in the middle of a storm can severely damage the plow trucks used to distribute it.
And like any DOT in the nation that deals with heavy snow cleanup and removal, Iowa’s DOT fights a constant battle to protect its vehicles from corrosion. That’s why a major part of the state DOT’s preventive maintenance program is pressure washing the salt and elements off every plow truck as it returns to the maintenance bay immediately after a storm.
Vocational trucks and equipment, whether it’s a snow plow, dump truck, aerial bucket truck, or even a chipper or lawn mower, are meant to work and perform specific tasks, at times in extreme weather and through harsh, off-road conditions. Therefore, their maintenance requirements can differ from line-haul tractor-trailers.
In order for vocational trucks to function efficiently in the field, one common denominator holds true for all of them: Proper preventive maintenance (PM) is king. And that usually means shorter maintenance intervals compared to their 18-wheel brethren.
As Chris Lyon, director of fleet relations at the National Truck Equipment Assn. (NTEA), points out, PM programs are needed to prevent unscheduled downtime. “The more complex these vehicles get, the more maintenance they require,” he says.
PM programs will vary based on the needs of fleets, duties and geographic location, he notes. And PM programs depend on drive cycle, duty cycle and the type of environment in which the vehicle operates.
When getting started, Lyon says it is crucial to clearly define the work requirement for a certain vehicle. He says it starts with defining the vehicle’s needs and specifying a proper vehicle to accomplish a task as required.
“Put things on paper before you go out and buy a vehicle,” Lyon suggests. “Defining operational needs first can decrease your maintenance costs down the line.”
Vocational needs
Joe Puff, vice president of truck technology and maintenance for NationaLease, explains that vocational city-type trucks work a lot harder than line-haul tractor-trailers and therefore require more PM work. NationaLease, a full-service truck leasing organization, has more than 700 service locations in the U.S. and Canada and a combined customer fleet of over 125,000 tractors, trucks and trailers.
For instance, Puff says, brakes in municipal or off-road vocational trucks could have half the life span of a line-haul truck. The same holds true for tires.
“When you think of a tire running down the highway in a nice straight line, the tire will last a long time,” Puff explains. “But that tire in a city application—twisting and turning and stopping and starting—will expire faster.”
And that kind of stress on a vehicle could result in higher maintenance costs. As a way to keep costs in check, he advises fleets scrutinize all components during the spec’ing process, particularly when it comes to vocational equipment. In tougher applications, Puff says maintenance professionals must take time with braking, electrical systems, and ECM (engine control module) settings. The key, he notes, is having a thorough understanding of the duty cycle and application of the vehicle before selecting components and ECM settings.
A “thorough understanding” involves knowing many factors, including the load amount and percentage of time carried, how many stops the vehicle will make, idle time, air supply demands, electrical demands, the appetite for fuel versus performance, terrain, and weather conditions—to name just a few.
“There are so many variables out there and you really need to understand all of them to spec the right vehicle for the application,” Puff says. “The wrong spec could lead to tens of thousands [of dollars] and downtime.”
Another practice that falls in line with a solid PM program is root cause analysis. According to Puff, maintenance technicians should analyze not only every unexpected repair, but why the failure occurred so future occurrences can be reduced or eliminated. He also notes that driver pretrip reports, past PM inspections, the vehicle application, and a thorough system inspection could provide useful insight during analysis.
“Once the root cause is understood, we could eliminate some of those failures,” he says. “Just going out and replacing a battery without understanding why it failed could lead to future problems.”
Puff adds that in high-demand vocational applications, it is most important to perform PM intervals on a timely basis and not exceed the OEM-specific guidelines; however, he advises those guidelines be tested periodically. In addition, he says it is important that certain components be tracked and serviced on their own schedule, such as coalescing and desiccant filters, valve lash adjustments, oil drains, DEF and DPF systems, wheel-end maintenance, and cooling systems. These components should be monitored frequently since progressive damage could become catastrophic, he says.
“Because the loads are much more demanding in the vocational arena, the need for PM intervals to be closely managed is important,” Puff maintains. “The most demanding application I’ve experienced is refuse trucks. The tire and brake wear is just incredible—even with maintenance and the best advancements in tires. With refuse trucks stopping and starting every hundred feet, it’s an eye opener to see how often they go through brakes, tires and other maintenance needs.”
In the field
Michael Webster manages the field operations fleet for the Forest Preserve District of DuPage County, IL. At times, he faces some unique challenges that other fleets might not encounter.
The district’s fleet comprises 1,300 pieces of equipment—from law enforcement vehicles, chippers and chainsaws, and riding mowers to larger tractors and bulldozers. Only about 200 pieces of equipment are on-the-road vehicles, Webster says.
The district has a primary fleet facility that operates with 10 employees, as well as a grounds facility and two garages that handle other repairs and maintenance issues. Because the field operations department maintains the forest preserve, grounds, buildings, vehicles, and equipment, its fleet puts more hours than miles on its equipment, Webster says. So, it has a PM program set up for four months or 4,000 mi., whichever comes first.
Law enforcement vehicles, mainly SUVs and Chevrolet Tahoes, however, are on a two-month PM cycle due to idling or being driven nonstop throughout officers’ shifts. They also go through brakes and tires more frequently than other vehicles in the fleet, he adds.
The department handles everything from public works to parks maintenance within the district, so vehicle upkeep is challenging. The county’s pickup trucks operate on both compressed natural gas (CNG) and gasoline, so mechanics have to be well versed and trained on CNG and potential risks, Webster says. Mechanics also maintain the county’s CNG fuel sites and are trained to repair CNG compressors, gasoline and diesel fueling pumps and tanks.
“It becomes hard to find qualified mechanics to hire because our field sets are so unique,” Webster explains.
The district’s heavy equipment mechanics spend a lot of time out in the field performing PMs on heavy tractors. “It saves us more time rather than having guys go out and haul it back to the shop,” he says.
What also makes this fleet stand out is that some technicians are responsible for fabrication and welding. And at times, techs have to fix strange pieces—like the district’s fiberglass milking cow, or the fiberglass horses displayed in the center of town.
“Coming through our fleet shop are sometimes unique and weird jobs that you don’t get through private sector,” Webster says. “It makes the job enjoyable for the guys because every day something unique comes through the door. It keeps things interesting.”
In addition to the daily tasks and mix of odd jobs, the department is responsible for plowing and salt spreading during snow storms, which is why one of the fleet facilities houses a drive-in heated wash bay. The wash bay is also used to wash and inspect vehicles when they come in for repairs.
Because of the various types of equipment within the fleet, tire maintenance and storage are sometimes challenging. Over time, the fleet has learned to buy more aggressive tire treads that hold up. But because there is limited storage space for all the different tires needed, Webster says he has to order from vendors that have the specific tires in stock to ensure they arrive the same day.
When it comes to keeping the fleet up and running, the biggest struggle is getting drivers to perform their pretrips. “That’s the way to tell us if the oil is getting low and it’s how we get the information we need to know here at the fleet to realize why it’s burning fluid,” Webster explains. “The pretrip is important for catching things early.”
And so is preventive maintenance. Ensuring equipment gets into the shop on time for PM service is critical to catching problems before they become maintenance nightmares. The fleet’s PM checklist, thorough inspection, and driver pretrips are the most critical elements to keeping costs down.
Iowa at work
Iowa’s DOT has a fleet of nearly 1,000 trucks—900 of which are snow plows, mostly International models. Others include bridge inspectors, semi-tractors, aerial bucket trucks, and other specialized-use trucks. But because the fleet mainly deals with snow removal, inhibiting corrosion is the top priority.
During a typical weather event, the state could see 10 to 12 in. of snow. According to fleet manager David May, the department spends considerable time pressure washing trucks to remove salt. He explains salt ends up in the trucks’ dump boxes, brake components, and frame rails, which are very expensive to fix.
“We try to avoid replacing them when necessary because that’s pretty much a death sentence for the truck from our fleet’s perspective,” May says.
And with excessive washing comes more rust. One of the department’s most valuable weapons is its grease gun. Greasing the fittings has become part of a PM program to prevent corrosion and rust caused by the environment and wash cycles.
Another maintenance challenge the department faces is that its snow plow truck fleet tends to get hit a lot more than most truck fleets on the road. The department uses wing plows that extend from the side of the truck and go one lane out to the side either left or right. So, if a wing is extended on the right side of the truck and visibility is poor, drivers don’t see the wing and they end up hitting the plow on the side.
“In any given storm event, we can have a half dozen or dozen collisions normally with us being run over from behind,” May says. “Generally, we come out ahead on the exchange because we tend to be larger than they are. We tend to have a lot of hits from behind from semi-trucks. No one comes out okay from that.”
One of the department’s best maintenance practices is having the same mechanics assigned to a garage, May explains. The department operates 100 garages statewide.
“We’re not a centralized fleet; most fleets tend to have a home base somewhere,” he says. “We tend to be distributed across the state in a uniform fashion. We distribute technicians that way, which gives them the opportunity to . . . work on the same trucks all the time so they can develop an understanding of those trucks.”
When it comes to maintaining the other vehicles within the fleet, May says practices are similar to other on-road fleets. Maintenance intervals for the state’s fleet of 30 semi-tractors are in line with OEM recommendations, and the same goes for the small fleet of bridge inspection trucks and their aerial booms.
Ultimately, maintenance practices for vocational vehicles vary depending on the operation. And, as Puff suggests, fleets should truly understand their unique operations; otherwise, they’ll end up with only the basic, run-of-the-mill settings over what might actually work best for their needs.
