Gas tank fill too slow

[San Diego Ron]

Filling add on gas tank takes forever...fuel back-up in line to tank shuts off station pump. There is a vent tube connected.

[donandal]

Is that a PVC elbow?

That elbow bend looks too sharp to flow well.
Is the flexible rubber hose ribbed on the inside also?
That could cause turbulence in the flow also.

[ranger danger]

I would change the 90 for a 45. If that hose is a radiator hose, be careful! Gas rots them out pretty quick and then you have trash in your tank, fuel lines and, eventually your carb!

[San Diego Ron]

Yes it is a PVC elbow (only thing I could find to fit my needs) and the ribbed hose is for fuel not a radiator hose, thought it has smooth inside but had better double check that. Tried 45 elbow but caused too much of an uphill in line to tank.

[indymachinist]

That pvc elbow has got to go. That is not safe. It is 100% your slow fueling issue anyways.

[San Diego Ron]

I agree the PVC should go...but what can I use to plumb this thing? Tried other metal elbows; exhaust tubing; copper fittings...nothing correct size.

[57taskforce]

Could you modify a filler neck from another vehicle to make it work? On my 3100 I used an 80s k5 filler for my stepside fender mounted fuel fill.

[old51sedan]

I'd try an exhaust shop, find the size you need and have it bent or welded to fit your application. Good luck

[57larry]

is the vent line clear?

[67 chevelle]

Originally Posted by 57larry

is the vent line clear?

My thought also , and a brass or copper elbow

[duallydude63]

i had a custom gas neck made from muffler tubing... i agree with old51sedan !!!

[waco]

Check that the vent line has no low spots in it to cause it to hold fuel, thus making it useless. I had this problem on anold motorhome i had a while back. Good luck.
Andy

[KY_GMC]

If this is a Blazer tank, there should be another vent port on the passenger side. Connect a hose with a rollover vent to it and stick it up in the bed side. It will allow air to flow out when filling and air to flow in when in use. I actually had to put two of these vents in to get mine to fill properly, one on each side of the tank.

[68is4me]

Also agree on the exhaust pipe. I have used this company for some hard to find things.

http://www.fillernecksupply.com/90-d...eatured&page=1

[68is4me]

Oh and forgot to say make sure you don't have any kinks in the tubes. Kind of looks like the rubber hose has a bit of a kink in it.

[San Diego Ron]

Thanks for all the help and suggestions for this problem, as soon as fuel level drops I'll take truck to local exhaust shop to have them make up new fill tube. Just curious as to why using PVC elbow is such a bad thing, not like it is submerged in fuel all the time...we do use plastic gas cans.

[wbc409]

It's a different type of plastic. Just like rubber lines different plastics are engineered to work with different chemicals. It doesn't have to be in direct contact with the fuel. Many times the vapors are just as hard on parts as the chemical is.

[WB72]

I moved my tank last year, I was told by an old timer to get as much vent as possible to avoid the backing up of fuel when you fill the tank. My tank had 2 extra lines so I used them both as vents. I ran them all the way up to the fill cap area.

To change your 90 degree PVC, go to a parts store ( I went to Acklands-Grainger) and get them to look up 90 degree fuel fill hose. They are surprisingly easy to find. the first place i checked had 4 in stock. in two different sizes. They run around $30 CAD, peace of mind.

[San Diego Ron]

I do have a capped off elbow on top of tank I could use for another vent line, will use that and still have muffler shop rig up something for fill tube. Thanks!

[San Diego Ron]

May have problem resolved, local muffler shop bent a pipe for me and welded it.

[San Diego Ron]

Back together.

[HO455]

That's much better looking! How's the flow?

[darrellyates]

Hey everyone.... I have been in the plastics field for over 30 years, and can tell you why not to use PVC fittings. PVC has extremely poor chemical resistance, (why it's easy to glue) and gasoline will absolutely destroy it in no time. The only plastics good for fuel lines are nylon. HDPE, used in gas tanks, will also work. Most new fuel lines are nylon, and tanks are blow molded PE. Some issues with PE and vapor barriers, so lots of new tanks are multi layer. Your hose should be Viton rubber if you're ever going to have any ethanol fuel (even 5 or 10%) as the ethanol will attack EPDM rubber as well.

Glad you got one bent at the muffler shop, that's always my go-to move for fuel neck issues.

There are lots of chemical resistance charts on-line for plastic and rubber. You can search simply with those criteria on google, "chemical resistance chart for plastics / or rubber"...

Thanks for listening.

[San Diego Ron]

The flow is 10 times better, not perfect but much better, now able to hold the nozzle without it clicking off.

[slikside]

Originally Posted by San Diego Ron

The flow is 10 times better, not perfect but much better, now able to hold the nozzle without it clicking off.

That's good....better is better!

Maybe it's the photo...kinda hard to tell, but it looks like the hose between your new filler, and the tank is slightly "uphill"? Like the end of your filler neck is lower than the tank opening. If so, I imagine that would slow the flow somewhat.