Foaming diesel

Caused by heat.

On the fords from that era they used the same fuel tank a the gas engine with a long breather tube that caused the foaming you see, When they switched to the 6.7 they chanded the tank configuration and tube length and no more foaming issue

Your RATE of fill will also cause foaming. Need to stay away from large nozzles like a truck stops.

bgum wrote:
Caused by heat.

I've noticed that it's worse when it's hot out.
I have to wonder if it's also worse when we've been on a long run and the fuel in the tank is hot (from cooling the HP pump). Does the cold fuel hitting that warm diesel and warm fuel tank cause even more foaming?

Look up "harpoon mod" on your favorite Ford diesel forum. This is a mod on earlier Fords where you shorten the vent and filler tubes going into the tank and results in faster fill ups. It allows more fuel to enter the tank before the foam backs up into the filler tube and shuts off the pump. Not sure if a similar mod exists on your year of truck but worth looking into.

http://www.guzzle7pt3.com/harpoon.php

I fuel all kinds of diesel powered heavy equipment every day. Foaming fuel is common regardless of tank configuration. Reduce delivery rate when nearing full to solve this. Listen for the change of tone when the fill tube begins to fill.

Barry W wrote:
Foaming diesel is a puzzle to me. When filling my 2006 f350 it takes forever to get a full tank. If I don't allow the foam to dissolve I miss about 4 to 5 gal from filling my tank. I have pumped thousands of gallons of diesel to John Deere tractors and I had zero foaming issues. Anyone else struggling to fill their ford trucks? Barry

It was the design of the fuel tank and filling system they used in the truck of that and the previous generation. when I changed from my 99 to my 2014 it all went away and I can use the truck stop pumps if I want to now as the hole is large enough for them from the factory.

The fuel is getting aerated by the path it's taking to the tank. We've got a couple of diesel tractors where the front filler neck is molded to go around the operator platform and takes a weird shape to get to the main part of the tank. Like you the last 5-10 gallons is tedious as the fill neck area fills with foam. The other tractors that have short filler necks that lead directly into the main tank don't foam at all.

Thanks, I was just curious if I was alone with foaming diesel. I think I'll keep the Ole ford. Barry W

enblethen wrote:
Your RATE of fill will also cause foaming. Need to stay away from large nozzles like a truck stops.

DITTO!