• Periodic inspection of turbochargers for internal wear.
• Thorough injector maintenance, including adding injector cleaners and having injectors replaced or reworked as necessary.
Operate the engine at an appropriate rpm, normally at or above the torque peak, when running continuously in heavily loaded, full-throttle situations. “A driver needs to pay attention to an increase in the frequency of active regeneration cycles, loss of power, and a decrease in fuel economy,” says Paccar Parts Business Development Manager Larry White.
Picking the shop
Most DPF cleaning is handled by truck dealerships. DPF cleaning equipment is often too expensive for small fleets. For example, the Donaldson system costs approximately $20,000, Emissions Group Business Development Director Fred Schmidt says, and achieves payback for customers who do more than 50 cleanings a year.
The service typically costs from $250 to $700 – a wide range because systems and procedures vary. “Cleaning methods include compressed air or heat or a combination of both,” Giguere says. “But some filters may be sensitive to high temperature or pressure.”
One sure approach is using a technology the manufacturer has developed. Giguere notes Detroit’s method, performed in Detroit’s network of reman centers, of treating the interior surfaces with a liquid is “substantially different from the methods used by other manufacturers.” Detroit Engine and Component Marketing Manager Brad Williamson recommends utilizing the reman exchange program to swap a dirty DPF for a cleaned one. Detroit’s reman units are covered by a one-year warranty with no limit on miles, and the change interval for a DPF cleaned with its process has the same recommended service interval as a new one.
Volvo also encourages owner-operators to exchange with a factory-reman filter. “Cleaning a DPF involves more than just using an industrial vacuum cleaner to remove soot,” says company rep Ed Saxman. The reman filters have also undergone ultrasonic inspection to detect anomalies.
Another plus for manufacturer recommendations: maintaining your warranty. “If you have the unit cleaned using an unapproved method, it could alter your warranty,” says Pacific Power Products Emissions Business Unit Manager Gary Parsons. Look for a cleaning process “that is documented step by step. They should be keeping records that will verify that each step of the process.”
Both Navistar and Paccar partnered with DPF-cleaning equipment manufacturer FSX to develop cleaning processes.
DPFs as maintenance tools
One DPF downside is it may mask serious engine problems that used to be easy to diagnose. On older engines, when you saw white or black smoke streaming from your exhaust stacks, you knew you had a blown turbo, a faulty injector, worn rings or other issues. Today’s DPFs will let little of that smoke escape.
“That is a general concern for the entire industry,” says Rakesh Aneja, senior manager for product engineering with the Daimler Truck Group. With the filter masking exhaust smoke, “the diagnoses become more challenging. It may lead to aftertreatment failures if it is … loading up the filter more and more.”
Frequent clogging can warn of a problem with an injector, an air handling system or oil consumption, says Myron Birschbach of Inland Power Group. Such early notice could help reduce repair costs and potential downtime.