"We use all three tests to certify the DPFs before we send them back to our customers," he says. "Because we've been doing this so long, we've been able to plot these results vs. time in service, to see just what kind of service life we can expect. For example, when we do hit the Green Tag range--very near OEM spec'--that's very good because we've gotten almost everything out of there, and you're not leaving ash in your filters that causes problems.
"When you get it restored to OEM spec,' you take one variable out of the equation; that's one less thing the fleet manager's got to worry about," Taylor says. "Now, his expensive DPFs that averaged between $5,000 and $8,000 apiece, are being properly restored to OEM spec,' and you can get years of life beyond warranty if you clean them this way. If you don't clean them right and certify them, then you've got a ticking time-bomb in these trucks. For example, Mister Nicholson's fleet of 900 Caterpillar-powered Kenworth trucks, he's looking at a DPF on every one of those. He's looking at literally millions of dollars worth of DPFs that need to be properly cared for, and if they're not, then he's facing, not too far out, another variable cost that could be devastating to his bottom line. That's why it's critical that he get them cleaned to OEM spec' and then have to records to back it up."
There is a simpler way to approach DPF cleaning, of course. A DPF exchange program, such as the one now offered by Mack Trucks, allows customers to bring in a truck for DPF service and simply have the dirty filter element swapped out for one that has already been cleaned. It's a much faster service, obviously, and will appeal to a great many users who simply don't want to be bothered with lengthy, inconvenient DPF cleaning experiences.
Nicholson, for his part, is skeptical that any fleet operator would be willing to take this route. A fleet maintenance manager who has a top-flight maintenance program might not like the idea of trading a DPF from a truck that he knows has been well taken care of for one from unknown origins.
"If you get somebody else's unit, that has had various thermal events that have happened throughout the life of that DPF, you might get one that's a grenade waiting to go off," he says. "It's a big difference for us because we are a 100 percent APU-equipped fleet. Why does that make a difference? Well, because our idle time is nowhere near what a normal fleet's, that idles all the time, might be. So if I roll in someplace, do I really want to take the chance of getting somebody else's DPF from a fleet that has an average of 45 to 50 percent idle time when ours is in the single digits? No, I really don't."
Taylor, whose company makes the DPF cleaners used in Mack's exchange program, sees it both ways. "Many fleets want their own DPF coming back to their own truck, and they want to be able to keep a database on it of cleanings and recoveries and they want to track it from cradle to grave," he says. "Others need the convenience of an exchange program to reduce downtime."
Tick, Tick, Tick
There's that tick again. Is it an alarm clock, or a time bomb?
When Frank Nicholson heard the ticking, he decided to be proactive, and even though he's had his share of DPF troubles, he seems to have averted disaster. He's got the DPF cleaning routine down to four hours, and his dealer is ready to start servicing the first of his 900 DPF trucks. Will the rest of the industry be so lucky?
"Early on, the information we got was that you roll this device up, you hook it up on the truck, and that's all you do, but that's not necessarily the case," Nicholson says. "As far as cleaning, it could be anywhere from $500-600 to, we've had some close to $2,000. You get into these situations where sometimes you're at the mercy of a dealer where you might not be as important to them as the next guy. In our area and at certain dealerships, we're a big fish in the sea. But when we get out to the west coast, we're a little minnow, we're nobody. So it makes a difference, unless you've negotiated a deal. That's what we've done; we've done some negotiating with our facing dealers, and we've said that we're going to support them by sending our units to them, and they're telling us that they're going to support us by giving us negotiated prices, but I think the industry needs to know that if you're just going to roll in anywhere and get your DPF cleaned, that's not going to be the case."