Having good time with the 1984 F150, I will have to post a pic soon but I haven't even washed it yet! So the rear tank filler tube (metal and good condition) transitions to filler hose (rubber, torn and booted), the clamp joining these two is either under years of road grime or under a cloth wrap boot material that is sealing the damaged rubber hose, ugh. if I had a dremel cutoff wheel handy I would split the clamp and start peeling away the layers but I don't so I started cutting the rubber back toward the clamp and encountered a ribbed plastic? inner hose (venting?) I don't know if I nicked it with the razor knife and don't really know how to proceed. help & advice pls.

Also for fun I fished a bare air plug out from the other end of this filler tube assembly (behind the spring door that is under the fuel filler cap! anti siphon strategy?

 

Would like to see this "bare air plug" you talk of?
Is your truck a long bed or short bed and you said rear tank does it also have a side mounted tank?
Would help to find part numbers for the hose.

Yes that plastic tube inside the rubber/metal is a vent and with out it will be hell to fill the tank short of a trickle.
The plastic tube goes into a fitting at either end to hold it into place.
Sometimes it is easier to pull the bed to work on the filler hoses and vent tubes.

That rubber is not radiator hose it is made for fuel. If the dealer cat get them try a boat supply store for it. Now I thing the rear hose has a bend but with ne hose it should bend.
This is my custom rear tank install on my flare side using style side & flare side parts.

I don't know how well it fills yet, still rebuilding the truck.
Dave ----

 

Thanks for the pics, that is like what I have. Strange my 2001 Econoline didn't have the vent hose in there... I am hoping the rubber fuel line they have at my auto parts place is flexible enough to make this connection without impeding flow to the rear tank, I used them for the large diameter fuel line on the Econoline and it seems like it had to make more of a turn for its mid-ship tank (over the tall frame rail of a E350) than this rear tank does. Here is that fitting I found:


not connected to anything and showing exposure to years of gasoline...

 

That is an air chuck for a air tool, where was that in the system?
Wonder if it was installed to vent the tank?
I have seen posts that even with everything in place you still cant fill too fast.
So my fingers are crossed mine will be ok as it was all put back together like the factory had it.
Dave ----

 

 

Thank you Bill for posting that up.

Dziwei, After looking at the pictures above, yours being the top one, I had to look at pictures of my flare side custom rear tank install to figure out the picture.
The style side rear metal filler neck is long and has a bend to it.

Then from the picture above it should be a straight rubber hose to the tank.
You can see what looks like a divider in the tube, that is where the plastic vent tube gets inserted. That divider goes all the way to the top where the flap door is.
The tank also has a divider type deal that the plastic vent tube goes into.

On this anti siphon coupler, are you talking about that little spring loaded flapper door? If so that's not what it was for.
Back in the day gas stations sold un-leaded and leaded fuel. So you would not put leaded fuel in a un-leaded car/truck the filler necks had that door and a small opening.
Leaded pumps had a larger nozzle and would not fit into that small opening.
Now days all stations only have un-leaded fuel and why new car/truck don't have that small opening any more.
Dave ----

 

Thanks for all the feedback! I bet that $10/ft. rubber fuel line at my local car shop with work great. I remembered incorrectly; that air tool fitting was at the tank filler neck when I pulled the rubber fuel hose off the tank! but couldn't tell if it was at the end of the vent tube or not... weird, just weird.