12,500w onan generator fuel filter question

[Bottomland4x4]

How the heck are you supposed to the fuel filter on the 12,500 onan? It's buried just inside the panel. Anyone here have any tips or tricks for changing it?

[bushpilot]

its a tedious pain in the arse

some units have a trap door (like this one)...mine does not

https://www.youtube.com/watch?v=4G8TjuZfyHE

[Bottomland4x4]

My old toter with a 7500 onan had the door, this one does not. According to the manual you are supposed to go through the side access panel. It's about impossible to get a wrench on the lines, maybe it takes a stubby wrench?

[bushpilot]

I've done mine a couple of times, I've used line wrenches to keep from twisting the aluminum fuel line....again its a PIA.

Ive thought (every time i change it) that i should add an inline filter PRE generator and just change it....assuming i could put one someplace that has easier access.

[Doug Ambrisko]

I added filters that could separate water ahead of the generator and Aquahot lines to deal with B20 diesel.

[bushpilot]

Doug -

got any pictures (for mounting ideas)?
we don't have aqua-hot but id much rather change an external filter (and benefit from water separation) for the generator.

[petrel]

I watched a Cummins/Onan specialist fight one once. He never complained, but it sure looked like I'd skin a few knuckles doing it.

I like Doug's approach too, but I have no idea where I could install that secondary filter that would be practical to service.

Now that we bring it up, servicing the air filter on the 12.5 is no cake walk either.

[Doug Ambrisko]

I used al. angle to mount the spin mounts to and then mounted the angle to the box;s frame rail that sits on the truck's frame rail behind the tank. I figure if I make a mess changing the filter or dumping the water I don't care there. I have long arms so I can reach them okay. It was a challenge to find the spin on mounts. It seems most dealers don't carry them. I guess they figure them come stock on their trucks. I got a couple at a generic truck parts place.

I mounted them near the tank since that is were the lines for the accessories are so it was easy to tap into them. There are a bunch of lines in the picture since there are 2 return lines as well.

Cummins/Onan requires the water separator for B20 warranty support. I think they wanted a 30 micron filter. I tried to order the Onan version but that was hard to find so I went generic. In general I try to avoid B20. Fortunately the CFN station that I fill up by our house is straight diesel. It seem all the truck stops in California are B20 now.

[bushpilot]

Originally Posted by petrel

Now that we bring it up, servicing the air filter on the 12.5 is no cake walk either.

its not any easier on the 10k either

[neetchracer]

I just did mine this summer. you can take the mount nut loose, then pull the filter out of the box. The fuel lines are long enough to do this. Loosen lines, change filter, repeat backwards. Not that bad.

[Bottomland4x4]

Thanks neetchracer, I will give it a try. I took the motorhome to get it serviced by speedco. They did a good job on my last toter, but they were lost it seemed this time. I understand they were just bought out by loves, but I will not go back, I had to look up how to change the air filter on the generator for them. I just couldn't find anything on the fuel filter at the time. The only good thing was they had all the filters in stock, I wish I would have had them give me the fuel filter, as I would install it myself. I will do it my self next time, you want it done right, sometimes you have to do it yourself! Lol!

[bushpilot]

NAPA carries the generator filters.