Community Forums

clafro · 06-27-2022, 12:15 PM

Does anyone else have this kind of corrosion on their remote Fuel Filter. Should we be concerned? We have only had the coach a month and put this on our punch list for the dealer to check. I’ve changed the fuel filters on our Phaeton a few times and never saw anything like this. The freightliner chassis had a different primary which I feel had a better fuel / water separator.

Flyer15015 · 06-27-2022, 12:28 PM

I would not be concerned.
I left a set of brand new wrenches out overnight on a picnic table.
Came out the next morning and due to the dew, they were all rusted.
Leason learned!

Mike in Colorado

Argosy · 06-27-2022, 02:05 PM

The bracket and threads on the fuel line in your first picture also look like they're rusting. I'd look around for more rust on the engine then above for a leak or something funneling rain to those areas

n2zon · 06-27-2022, 05:07 PM

Water can get in and collect on top of the filter, causing rust. It's of no real concern and eventually new filters will look better (but work the same way!).

Skip426 · 06-28-2022, 10:12 PM

The top of the filter , from the seal to the outer rim , is bare steel and will rust .

In some states faster that others .

DRM901 · 06-29-2022, 05:31 AM

Ours, on a 2014 Tiffin Allegro Bus 37AP, does this every time. I guess you could spray it with silicone, but you should change it every year, so it won't rust enough to matter.

Sent from my SM-G973U using iRV2 - RV Forum mobile app

Ray,IN · 06-29-2022, 10:22 AM

Quote:

Originally Posted by clafro

Does anyone else have this kind of corrosion on their remote Fuel Filter. Should we be concerned? We have only had the coach a month and put this on our punch list for the dealer to check. I’ve changed the fuel filters on our Phaeton a few times and never saw anything like this. The freightliner chassis had a different primary which I feel had a better fuel / water separator.

I would bet there is a water separator/filter somewhere in the engine compartment. As far as I know Cummins requires 2 fuel filters, water separator filter is also coarse fuel filter, and a final filter which should be 2 micron final filter.

DRM901 · 06-29-2022, 07:11 PM

That is the fuel/water separator - FS1003. The fuel filter had a plastic housing - FF63054NN.

Sent from my SM-G973U using iRV2 - RV Forum mobile app

Ray,IN · 06-30-2022, 03:50 AM

That is indeed odd, my water separator has a plastic bowl on the bottom of the primary fuel filter. That bowl has a knob to open and drain water away.

DRM901 · 06-30-2022, 08:15 AM

The parts I listed are for a 2014-present (I think) Cummins ISL 450 hp. That is what the OP has.

Sent from my SM-G973U using iRV2 - RV Forum mobile app

clafro · 06-30-2022, 08:38 AM

Quote:

Originally Posted by clafro

Does anyone else have this kind of corrosion on their remote Fuel Filter. Should we be concerned? We have only had the coach a month and put this on our punch list for the dealer to check. I’ve changed the fuel filters on our Phaeton a few times and never saw anything like this. The freightliner chassis had a different primary which I feel had a better fuel / water separator.

Yesterday I checked a few new Allegro Buses at Lazydays and they all had this corrosion going on. I'm now thinking the problem might be Galvanic Corrosion.

Galvanic corrosion (also called ' dissimilar metal corrosion' or wrongly 'electrolysis') refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte.

Argosy · 06-30-2022, 03:49 PM

Quote:

Originally Posted by clafro

Yesterday I checked a few new Allegro Buses at Lazydays and they all had this corrosion going on. I'm now thinking the problem might be Galvanic Corrosion.

Galvanic corrosion (also called ' dissimilar metal corrosion' or wrongly 'electrolysis') refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte.

The aluminum usually corrodes faster in that, and it's limited to contact area.

n2zon · 06-30-2022, 05:12 PM

Quote:

Originally Posted by clafro

Yesterday I checked a few new Allegro Buses at Lazydays and they all had this corrosion going on. I'm now thinking the problem might be Galvanic Corrosion.

Galvanic corrosion (also called ' dissimilar metal corrosion' or wrongly 'electrolysis') refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte.

Hmmm. The filter has a rubber (probably neoprene) seal that prevents contact between the aluminum filter housing and the steel filter case. There's a steel threaded pipe inside the filter housing that has direct contact with the aluminum and the filter, but as it's bathed in fuel it does not corrode.

It would be academically interesting to know whether the connection via the threaded pipe is enough to induce surface corrosion on the unpainted part of the filter case, but honestly--this isn't a *problem*. The rust will go away when you replace the filter and come back not terribly long thereafter, but it will never hurt anything.