67 Fuel tank problems

[cancow]

My in cab fuel tank is only holding 10 gallons. I have been told that it is a 18 or 22 gallon tank by various sources. If this is true what could be the problem? Also, when full the gauge shows 3/4 of a tank, and is empty at 1/4. I have never used the second tank for i dont know how to use it yet... How does one know if the secondary tank works? do i just switch the switch for tank 2? Is there an electric valve i can check to see if it is working first? Thanks

[OldBlue67]

We can probably assume that your tank is holding the same amount as usual, but your gauges are lying. I'm having a similar problem with my Aux tank. I don't think the problem is in the gauge itself (at least for mine) but in the readings its getting from the tank, float problem? I'm rather clueless in that department

switching from the in cab tank to the aux is simple. there should be a switch on the floor on the drivers side (for changing fuel wise)and another small switch under the dash, at least it is for mine (for changing gas gauge wise). All you've got to do is move the floor switch from "main" to "aux" and then switch the one under the dash over (I cant remember if its labled, but if you've only got two tanks, you've only got two options ) and that should do it for ya

....hope that made some kind of sense

[cancow]

Yep, those are the switches i have. Still, do you really think the bed tank is 10 gallons? I am almost certain i have read that both tanks are over 18 gallons each.

[FORDification]

If you've got the factory auxiliary tank that feeds from the side of the bed like that on my truck (pictured on this page), it's a 25-gallon tank.

[flyboy2610]

False readings can be caused by a bad ground. You might try cleaning the area around the ground wire on the tank and tightening it securely.

[cancow]

False readings can be caused by a bad ground. You might try cleaning the area around the ground wire on the tank and tightening it securely.

Ok i will try that, but it is more the 10 gallon capacity that is bothering me right now. I just drove 2200 miles and i had to stop ever 80 miles or so for gas. The ower i got the truck from said he only tried to use the aux tank once and was stranded so i have not tried it yet, hence i have been only using the in cab tank.

Fordification. Yes i do have the aux tank. 25 gallons eh? Sounds great! I better clean it out first though.

[OldBlue67]

Still, do you really think the bed tank is 10 gallons? I am almost certain i have read that both tanks are over 18 gallons each.

oops sorry what I ment was since the tank holds more than just 10 gallons, its probably holding "the same amount as usual" (mine fills up at about 20) it was just your gauges "lying" and saying that you were empty after 10. does that make more sense? ....cause I think I'm confused now

[cancow]

oops sorry what I ment was since the tank holds more than just 10 gallons, its probably holding "the same amount as usual" (mine fills up at about 20) it was just your gauges "lying" and saying that you were empty after 10. does that make more sense? ....cause I think I'm confused now

I know the gauge is wrong with 3/4 being full and 1/4 being empty, but i do mean it is ONLY holding 10 gallons. for 3 days i filled to the TOP and almost ran out of gas 3 times and rolled into a station and filled up 10 gallons to the top. Somehow half the tank is blocked but how? I am as confused as you, believe me!

[FORDification]

...but when you're filling up, your tank really isn't on empty...your gauges are just SAYING that it is. There is still plenty of gas in the tank. This is why it's probably a good idea to get that fixed.

[cancow]

...but when you're filling up, your tank really isn't on empty...your gauges are just SAYING that it is. There is still plenty of gas in the tank. This is why it's probably a good idea to get that fixed.

There may be another 10 gallons or so left, but it does not get to the engine. Like i said, the engine runs out of gas after beind down 10 gallons... But yes, it is a MUST fix.

[FORDification]

Hmmm.....something's not right here. First of all, let's make absolutely certain we're talking about the same in-cab fuel tank. Does it look like this:



If not, then somebody's swapped in a different tank. (I saw a '67 in a salvage yard a while ago that had a tank back there that was NOT stock. CLICK HERE to view a shot of this thing...it's huge!)

If the first pic DOES look like your tank, then you do have the stock 19-gallon version. If you fill it all the way up (verified by the gas station pump) and then the engine actually does run fine for a while but then runs out of fuel after the 8-10 gallon mark, then I'd almost say it sounds like the fuel tank pickup is too short, not reaching to the bottom of the tank. The float assembly could possibly have been replaced at some point by a previous owner, using an incorrect assembly that doesn't reach all the way down. Maybe it's time to pull your float/sending unit and take a look.

(P.S. - I'm moving this thread to the correct forum.)

[cancow]

I'd almost say it sounds like the fuel tank pickup is too short, not reaching to the bottom of the tank..

That could explain it for it is the factory tank alright. I am waiting for my factory manuals set. Then i will see if i can figure it out. Thanks a lot for all the info! Great site!

[FORDification]

I guess I should also clarify what I just said. I said "The float assembly could possibly have been replaced at some point by a previous owner, using an incorrect assembly that doesn't reach all the way down."...I meant the pickup tube doesn't reach all the way down. The two are seperate. But you should be able to see the pickup tube when you remove the float assembly.

[bumt72]

Could I float the suggestion, smirk, that instead of trying to get the in-cab tank working you get the auxilary tank working and use that one instead. I strictly use my auxilary tank, and will be removing the in cab tank in the next month or 2, for more storage behind the seat.

Kep

[cancow]

Could I float the suggestion, smirk, that instead of trying to get the in-cab tank working you get the auxilary tank working and use that one instead. I strictly use my auxilary tank, and will be removing the in cab tank in the next month or 2, for more storage behind the seat.

I actually thought of converting the in bed tank into a tool box. . Maybe cut off the top of the tanks and put hinges on it or something like that. I do still want 2 tanks so if i find another tank i would like to put it under the back of the truck.