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- Jan 19, 2021
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- Toadless
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First - I’m posting this here because it includes diesel Class B, Super C, and both front and rear engine diesel Class A coaches, 2010 and later.
Second - Ill try to keep this brief, but as many have noticed, it’s a challenge for me.
So, the meat of the matter: Through my travails and angst with with my DEF/DPF/SCR system I’ve learned a lot and one of the most important things (I think) is this:
Change your DEF filter more often.
At least annually, but I’m thinking maybe even more often. It would depend on how often and how much you use your coach. If you drive it at least every other month and are passing a few gallons of DEF through the system each time, annually is probably good enough. If not maybe even every six months, or after it’s been sitting for months.
Rationale:
Everything I had read until very recently said the DEF filter has a 200,000 mile maintenance interval. So great - you can ignore it. Very few folks will ever see 200k on the clock. But, it also should be changed every three years or 200k according to Detroit Diesel. Volvo says every 150k miles or 4500 hours. Cat has a similar hour use standard. But this still applies primarily to vehicles that rack up a lot of miles. One of the problems with DEF is that it readily precipitates out salts in the from of nasty crystalized muck and that muck is not easily handled by these oh-so-fragile, underengineered, poorly designed (ok here I go again....) systems.
Anyway, the stuff solidifies and screws up the system: sensors, lines, pump, and of course the filter. And the filter, when plugged up makes the pump work harder, adding excessive and premature wear, and thus early failure (like mine). Had I known, had someone told me: “Hey, change that DEF filter more often - 200k miles is for big rigs that drive 200,000 per year dummy!“, I would have been more on top of this.
And that’s really the issue. Wedon’t drive that much by diesel engine standards, these filters are made of paper and deteriorate anyway (hence 3 years), but worse, these rigs sit more than drive and I think (my own opinion based on my own experience and research) that a lot of emissions issues could be avoided with an accelerated DEF filter maintenance interval, as stated above.
Conclusion:
So that’s it - do it or don’t, but you’ll probably be doing yourself a favor. And it’s cheap insurance - the filter is around $11 for a cheap chinese knock-off, $40 for a Bosch, $100 for one that says Cummins on it. And it’s easy. Easier than an oil filter. Anyone can do this. And if you have risen above doing your own maintenance, buy a filter and take it with you to your next maintenance appointment. That’s it. From all I’ve learned about this stuff, that’s the easiest, cheapest and most proactive thing you can do, and no one is talking about it.
Of course the other thing that is easily within your powers is to be very picky about the DEF you buy, paying special attention to the date code (once you learn to de-code it) and the conditions under which the stuff was stored. These things seem to be extremely important as well, but another topic for another day.
I guess that wasn’t brief, but an improvement for me.
Cheers, happy motoring, and best of luck with your emissions system.
Second - Ill try to keep this brief, but as many have noticed, it’s a challenge for me.
So, the meat of the matter: Through my travails and angst with with my DEF/DPF/SCR system I’ve learned a lot and one of the most important things (I think) is this:
Change your DEF filter more often.
At least annually, but I’m thinking maybe even more often. It would depend on how often and how much you use your coach. If you drive it at least every other month and are passing a few gallons of DEF through the system each time, annually is probably good enough. If not maybe even every six months, or after it’s been sitting for months.
Rationale:
Everything I had read until very recently said the DEF filter has a 200,000 mile maintenance interval. So great - you can ignore it. Very few folks will ever see 200k on the clock. But, it also should be changed every three years or 200k according to Detroit Diesel. Volvo says every 150k miles or 4500 hours. Cat has a similar hour use standard. But this still applies primarily to vehicles that rack up a lot of miles. One of the problems with DEF is that it readily precipitates out salts in the from of nasty crystalized muck and that muck is not easily handled by these oh-so-fragile, underengineered, poorly designed (ok here I go again....) systems.
Anyway, the stuff solidifies and screws up the system: sensors, lines, pump, and of course the filter. And the filter, when plugged up makes the pump work harder, adding excessive and premature wear, and thus early failure (like mine). Had I known, had someone told me: “Hey, change that DEF filter more often - 200k miles is for big rigs that drive 200,000 per year dummy!“, I would have been more on top of this.
And that’s really the issue. Wedon’t drive that much by diesel engine standards, these filters are made of paper and deteriorate anyway (hence 3 years), but worse, these rigs sit more than drive and I think (my own opinion based on my own experience and research) that a lot of emissions issues could be avoided with an accelerated DEF filter maintenance interval, as stated above.
Conclusion:
So that’s it - do it or don’t, but you’ll probably be doing yourself a favor. And it’s cheap insurance - the filter is around $11 for a cheap chinese knock-off, $40 for a Bosch, $100 for one that says Cummins on it. And it’s easy. Easier than an oil filter. Anyone can do this. And if you have risen above doing your own maintenance, buy a filter and take it with you to your next maintenance appointment. That’s it. From all I’ve learned about this stuff, that’s the easiest, cheapest and most proactive thing you can do, and no one is talking about it.
Of course the other thing that is easily within your powers is to be very picky about the DEF you buy, paying special attention to the date code (once you learn to de-code it) and the conditions under which the stuff was stored. These things seem to be extremely important as well, but another topic for another day.
I guess that wasn’t brief, but an improvement for me.
Cheers, happy motoring, and best of luck with your emissions system.
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