By Jim Park
Aftertreatment system maintenance is easier when you stay ahead of the demand.
We appear to be learning from our mistakes in aftertreatment system maintenance, but we still have a way to go before we’re at peace with the things.
Strictly speaking, diesel particulate filters, diesel oxidation catalysts, selective catalytic reduction systems and their associated hardware have proven pretty reliable over time. It’s not so much the basic hardware that stymies maintenance personnel, fleet managers and drivers, but the difficulty in predicting when maintenance is required or when upstream problems will cause downstream failures.
“The biggest problem I see is there’s just not enough attention paid to the preventive side of aftertreatment maintenance,” says transportation fleet maintenance consultant Bruce Stockton. “Fleets tend to wait until a light comes on or the system throws a code. By the time the light comes on, the problem could be such that the truck could be down for two or three days at a remote location. If fleets stayed ahead of the problems, maintenance on the system could be done, along with the regular PM work, in a day.”
Stockton says if some preventive measures were put in place at some prescribed time or mileage, much grief and downtime could be prevented.
“A lot of fleets seem to think that because the aftertreatment warranty goes out to 500,000 miles or more, they’ll hope that nothing goes wrong in the interim,” he says. “That’s like saying I bought a 500,000-mile warranty on my engine, so I won’t bother changing the oil.”
Based on Stockton’s experience working with many different fleets, he estimates the safe DPF cleaning interval for an over-the-road truck running 400 to 500 miles a day is 350,000 to 400,000 miles. He has tracked data on these intervals and says they can be applied fairly universally to trucks with fuel