Dual tank fill-up to top

PA12DRVR wrote:

ognend wrote:

eHoefler wrote:
The fill necks are too low. The after market bed manufacture has them too low.

Assuming this is correct - what is the fix? Thanks!

Had a sort-of-kinda-like problem on my recently sold dump truck. First thing to look for is whether the fuel fill spot ("fuel cap") is higher than the tank(s). Second, if the "fuel cap" is indeed higher than the tank(s), does the fill pipe run between the cap and the tank in such a way as to allow fuel to gravity flow down or is there either an extended run of level fill pipe or does the fill pipe even run "uphill" from the fuel cap before dropping down into the tank.

On my truck, it was the latter situation: there was a slight, very slight, uphill run between the cap and the first bracket on the hose. For whatever reason, it would fill fine until the tank was 3/4 full, then I couldn't get any more fuel in the tank...it would just come back out. I lengthened the bracket, had a local shop shorten and straighten the fill pipe (so it ran entirely downhill between the cap and tank) and the problem was resolved.

Another option of course is to put the fuel cap at a higher location on the bed, but that's probably difficult with the aftermarket bed.

Interesting. Well, I took photos and I found two things. Only the back tank has a 3rd hose that is capped (is that the vent hose)? Otherwise, yeah, there seems to be a slight drop but I cannot tell if it is sufficient or not. I am posting links to the photos.

Back tankhttps://pasteboard.co/T5MJxUeXoa2j.jpg
Front tankhttps://pasteboard.co/QrLKpvlaH9LL.jpg
Back tank drophttps://pasteboard.co/iEd5zn8f4OxH.jpg
Front tankhttps://pasteboard.co/EvLqBWXRm8cF.jpg