Fuel filler issue

[powerstrokinfirefighter]

Just picked up my OBS the other day, and the biggest issue I had on the trip back was putting fuel in it. The front tank would take fuel continuously, but very slow. The rear tank I could get maybe half a gallon at a time before it overflowed. The rear tank is new, but looks to be mounted correctly. There has to be a better way to vent these things seeing as it takes 20 minutes to fill the back tank. Anybody have this issue before? Fixes?

 

[wyomingtrucker]

I have the same issue with my rear tank but my front one fills fine.

 

[Patrick Feeley]

Everyone that has had an OBS has dealt with this. Some folks will keep a few chunks of 4x4 lumber to drive up on the driver's side (no joke). Transfer Flow used to offer fill neck kits (pricey) for our trucks that were supposed to work well. There are also lots of posts in various Ford Diesel forums on modifying your existing setup, but make sure you research that a whole bunch before hacking yours up (in my reading over the years there has been success and failure in the various ways that some go about it). Cheers!

 

[Tom S]

They are a little tricky to fill but not like you are describing. I expect something is fubar with it. I can fill mine OK but getting the nozzle in the right amount is part of the trick.

 

[Vinny07psd]

A great way to fix that issue is driving down to the Chevy dealership!

 

[old man dave]

Make sure the fuel filler hose is not kinked and runs at an upward angle to the filler neck.

 

[powerstrokinfirefighter]

I'm going to mess with it tomorrow some. The front works ok as long as I don't put the nozzle all the way in, but the back is impossible

 

[powerstrokinfirefighter]

A great way to fix that issue is driving down to the Chevy dealership!

Nah I'll pass

 

[Redpower]

Since I have put flatbeds on both of my trucks I've had this problem. The best way is to drive the truck up on a 4x4 or 6x6 and it will fill a lot better. I've also found that if I use a small fill nozzle instead of the large and turn it upside down, it will fill quicker too.
The problem on my trucks is there isn't enough fall going to the tanks and it won't flow as fast as the pump will flow.

 

[old man dave]

The real problem is that the tank vents do not work well. The OBS tank vent hose runs through the center of the fill line. You need to remove the nozzle restrictor plate in the filler neck, remove the vent line in the center of the fill line and add a rollover valve that will vent the tank externally back to the filler neck. The tough part is finding the right rollover valve. Some have cut a groove around a PVC pipe fitting that will fit the gasket of the existing rollover valve snugly, then plumb an external vent line to the filler neck and add a hose barb to the top of the filler neck for the vent line. Works just as good as the TransferFlow vent kit and costs about $50 for both tanks.

Straight PVC pipe coupling, slip/thread, 90*hose barb/pipe thread to fit, some diesel rated fuel line for the vent hose, a 90* brass hose barb to braze into the metal section of the filler neck and a couple of clamps. I don't recall the size of the PVC coupling, its either 1/2" or 3/4" PVC pipe. Then you can use the big boy fuel pump nozzles full blast. You can use a bench grinder to cut the gasket groove into the PVC pipe coupling.