Hello iw as wondering what could be the problem with my 1964 ford f-100 gastank it is mounted behind the seat liek it was from the factory but it only holds 5 gallons! when it has 5 gallons in it it overflows when i park it and wut is the capacity taht it is supposed to hold?

 

It should hold much moor than 5 gallons.
Pull the sending unit out and look inside with a flash light. Your pickup tube may have rotted off and needs to be repaired.

 

overflows from where? maybe there is a pin-hole rusted through on it?

 

How do you know it only hold 5 gallons? I mean, have you ran it till you get no more gas, or are you judging from the gas guage?

If you are running till she sucks air, then I agree, its the pickup tube. If not, then it may be the guage or the sender.

My sender was not working, and I was plugging fuel filters too often. So I pulled out the tank and gave it a couple of good rinsings. The stuff that came out made me want to puke.

I did this little manouver with the sender in place, but I have since decided that was stupid. But in any case -- all that banging around (a friend and I literally SHOOK the tank) seems to have shook loose my sender, and now all works fine again (6 months and counting). But I think a little gentler approach, at least to the sender would have been just as effective and avoided the risk of damage to the sender.

 

Acording to the owners manual, the tank should hold 17.5 US gallons. You probably do have a pickup tube problem if the truck runs out of gas after 5 gallons, and you probably have a sensor problem if it is reading empty on the guage. Also check the gas guage along with the voltage staleizer. Check the fuel pump for pressure. The tank is so high that it will actually gravity feed the carburator for a few of the top gallons in the tank. If you remove the float assembly to inspect the tank, be very very careful as to what you use to illuminate the inside of the tank. Remember, it has a lot of gas in it and one open spark is all you need to loose both the truck and possibly yourself. Even a flashlight could set it off. Best to use a sealed flashlight like one for a boat.

 

I'm still not convinced this is a problem with his pickup or sending unit and not that it just plain seeps gas when it sits still - We need more info methinks...

 

Maybe he parks on a steep sided mountain with filler neck to the low side

Solve problem w/ later tank, between rear frame rails. A 67-73 tank has exposed cap or use 74-79 for a gas door & pocket. Now stash a "Cold 6" & tunes where suicidal bomb used to bolt in. FWIW: Heres 2 more slick trix deals!

1 find 73-79 supercab, take split bench, bolt to your trax & bolt in your truck. Tilt pass side, backrest, forward to access "Cold 6" on the roll or fetch CD's to play.

2 Find 61-66 F500 or COE H500, grab big rubber fillerneck plug used for F & H Models w/ saddle tanks to seal hole where filler neck was. It's different & Gives bowties sumthin to discuss Bsides just gettin beat Ha! FBp