The video shows all the damage to the DPF (diesel particulate filter) on one of our MaxxForce 7 International diesel engines. This is the second diesel particulate filter that has failed this way. It seems to me this DPF has a definite weak spot. Only three years old and this “catastrophic failure” as the dealer called it has occurred on one of the eight MaxxForc 7 diesels we own with the exact same specs. Luckily after 2 failures they were both covered on warranty.
The first failure was on a bus that climbs a logging road every morning and gets plenty of work running up to temperature which is what has to happen to help keep the DPF cleaned out. The DPF obviously broke down from the heat and constant regenerations to keep it clean from soot and ash. It’s surprising to see this happen so soon but in reality our maintenance program will have to include checking these filters internally every 3 years.
This second failure (featured in the video) is on a wheel chair bus running at low speed in and out of the suburbs. This is definitely not good for the emission system. This brings up the question why put an emission controlled diesel engine on a light bus run picking up and dropping off students in the burbs? Hindsight is frustrating sometimes and after experiencing this mishap and the number of parked regenerations we’ve had to perform with these engines during a run I am going to strongly recommend going for a gas engine for our next wheel chair bus. I believe we are getting a couple of wheel chair buses next year.
I’ve heard propane engines are making a come back because of the clean emissions and higher reliability. The one objection to that is installing a propane filling station on site. The dealers are offering a huge break on installing the propane fueling infrastructure but there might be a minimum purchase worked into the package. I could see getting a bulk fueling station credit card and letting them look after supplying fuel. Running a couple of buses on propane wouldn’t make it too difficult to succeed going that route.
Today I priced out a new diesel particulate filter assembly for our 2013 MaxxForce 7 diesel. From the dealer they come in at $3300.00 with a $1600.00 core charge. With some research one of my other parts suppliers found a manufacturer in Ontario who sell them for a $1000.00 less and no freight. Not surprising the cost is going to remain relatively high for any emission controlled diesel engine. It’s all about keeping the waste product of emission out of the system. This thick sticky goop that invades every component in it’s path is not going away.