Warranty required fuel filter change interval

This is regarding 2015 NCV3 3500 (Itasca Navion). Per reading the maint manual, Service A is at 20,000 mi with no apparent time limit. In the text they say the fuel filter should be changed every 20,000 miles - corresponds to Service A, right? Except that, buried in the service chart under Engine, it says: "Replace fuel filter with water separator (after 1 year at the latest, observe date of installation)"

In light of these fuel pump warranty denials what are/should be people doing? Making a special trip in just to get fuel filter changed after one year even though Service A may be 10,000 miles off?

It's aggravating that you have to practically memorize the maint manual in order to sleuth out the fine details to protect yourself from warranty denial. I think their "helpful" service computer may actually lead some astray.

Just buy a filter and save the receipt to cover the date if you are worried.You could even return it if you are never going to replace it yourself

rollerbearing said:

It's aggravating that you have to practically memorize the maint manual in order to sleuth out the fine details to protect yourself from warranty denial. I think their "helpful" service computer may actually lead some astray.

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I totally agree. I am an advocate of doing EXACTLY what the applicable published MB documents say (neither more nor less). Easier said than done, though, since these recommendations change frequently. This in itself is not bad--they are presumably learning from experience. But, as you say, they do a simply awful job of keeping the different parts of the manual in sync with each other, and with the on-board reminders.

The requirement that you have discovered does NOT appear in the 2014 manual:



I suspect that it was added as a defensive measure against the ridiculous bio-diesel situation in parts of the US, or perhaps due to the kinds of fuel-system failures that are being discussed elsewhere in the list at the moment. Who knows? But I am quite sure that these changes are not random, either when they get more restrictive or less so, which is why I advocate paying careful attention to the fine print. They don't make it easy, though. There is another current thread in which the OP is convinced that he or she needs to replace their oil because of a time-based A-service icon on their dash, even though there is no such requirement from MB. Maybe they are right. More likely, though, it was an oversight in updating the firmware on the vehicle to match the changing requirements (N.B: I have no data on this). There is no real way to know, so everybody has to make their own choice. I personally believe in following precisely the written recommendations and paying careful attention to the fine print, which is what you seem to be doing as well.

Hayduke and Avanti

I am not one afraid to turn a monkey wrench, and have already been changing the oil at a more comfortable (to me) service interval. I just don't have any experience with MB and their warranty stance to know if I can get away with a receipt and my own labor. I've been planning on following Avanti's path of sticking to the book and I intended on taking all the "book items" to the dealer to avoid later arguments.

How has MB reacted to DIY labor with regards to honoring their warranties? I sure would like to just swap out that fuel filter myself if it's not going to burn me later.

rollerbearing said:

How has MB reacted to DIY labor with regards to honoring their warranties? I sure would like to just swap out that fuel filter myself if it's not going to burn me later.

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I have no direct experience about what happens in practice, but I will say that it would be TOTALLY illegal for them to quibble with a properly-documented DIY service. This is principle #1 of the Magnuson–Moss law. I very much doubt that under normal circumstances it would have any negative effect. As part of some larger p***ing match, though, you had better have VERY good documentation and follow the rules to the tee.

rollerbearing said:

How has MB reacted to DIY labor with regards to honoring their warranties? I sure would like to just swap out that fuel filter myself if it's not going to burn me later.

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I do my own oil and filters. I keep the receipts and take pictures of the parts. The only comment from my dealer so far is that Carl (sprintguy) recognized that I use the Oetiker one time use crimp clamps instead of the clic-r reusable style MB uses...I like fresh clamps...on my replacement fuel filter. I buy my Mann OEM equivalent filters from IDparts and my oil from Amsoil.