Fuel splashes out of tank when I make sharp right turn

[srea76]

My project had the tank in the back bed and I am moving it under the back bed. I recently bought me a weekend driver and the tank is original behind the seat. I filled it up last weekend and as I made right turns I would see gas in my mirror splashes out the filler tube. I thought maybe it was the cap because it was not insulated well. I ordered a new cap from classic parts and have the same thing happening. Was this normal on the original tanks?

[Scott>72-GMC]

Some people have issues with that and hate the cab tanks I haven't had an issue ever so I can't suggest a fix but I would think there would be one
Posted via Mobile Device

[69GWC]

Since its a vented cap your going to get some of this but it should not be a big amount.
Posted via Mobile Device

[srea76]

well it is not huge, but just hate seeing it come out and roll down side of truck lol. I thought it may be normal. Just another reason I am glad Im moving my project truck tank under the bed.

[gipper]

I actually have stains on my '68 GMC from that. Does not look good on a white pearl paint job.

[special-K]

Originally Posted by srea76

well it is not huge, but just hate seeing it come out and roll down side of truck lol. I thought it may be normal. Just another reason I am glad Im moving my project truck tank under the bed.

It's not normal. I've never had this problem before. Not sure what to tell you if you got a new cap. I've had them leak when the tank was just filled and parked with the left side sitting lower. The problem was a bad cap seal.
I'm wondering why you think it's bad for gas to splash from the tank fill in the cab,but ok to splash from the tank fill under the bed?

[Spartan]

I was wondering about this myself but frankly I'm baffled. I just make three left turns instead of a right.
Posted via Mobile Device

[72 K20]

The 69 C10 I had sloshed fuel when turning right or accellerating around a right hand curve,, my 72 K20 does the same thing. I've tried 3 different caps,,, it still sloshes fuel out until the gauge gets close to 3/4 of a tank.

[srea76]

Originally Posted by special-K

It's not normal. I've never had this problem before. Not sure what to tell you if you got a new cap. I've had them leak when the tank was just filled and parked with the left side sitting lower. The problem was a bad cap seal.
I'm wondering why you think it's bad for gas to splash from the tank fill in the cab,but ok to splash from the tank fill under the bed?

Well my tank fill under bed is behind license plate. So if it splashes under my project it just hits the ground. I am more worried about it getting on paint than anything on my weekend truck. Ill try to record it and show you guys what I am talking about.

[Rufton]

Originally Posted by Spartan

I was wondering about this myself but frankly I'm baffled. I just make three left turns instead of a right.
Posted via Mobile Device

Could try out for NASCAR

[bobs409]

My 71 did this too but it's not normal as mentioned. (does not happen with my other trucks) I have a locking gas cap on mine and for some reason, it's not compressing the gasket enough. Possibly from all the years of a gas pump handle hanging off of it?

I've tried 2 other gas caps, one of which works just fine on my 69 and even a new one and all the same thing. I tried lightly bending the inside of the filler neck to make the cap pull down harder but it didn't work either.

For now, I added a plastic shim to the filler neck. It's definetly "red neck" but does the job as it no longer leaks a drop! It's just an old plastic cap or plug or something I modified that I had in my junk drawer.

I don't see why everyone wants to change or modernize these old trucks. My gas tank is staying right where it is!

[bignbad]

never had an issure with this to.I would no to try to over fill you tank.I know people like to over fill there tanks (top them off) and this may happened and in the warmer climates fuel expands more. Stick the nozel in the fill tub flip the handle on it to lock and when it shuts off do not try to top the tank off

[special-K]

They advise not to top a tank off too far,for other reasons. When it clicks off,that's it for me. I would fix whatever the problem is. It may not occur with the new set-up. Leaking at the rear of the truck may not hurt paint,but if for any reason there are any sparks from under the truck they go straight to the rear.

[68gmsee]

Gas caps aren't made like they used to be and the ones I've bought always seemed to leak. Also, another possibility is the neck itself. It could be warped.

I bought a cap from one of the local vendors on this site (don't remember who) and it was a better fit but still leaked a little. I took the rubber seal off one of the other caps I've bought and doubled up on it. It's harder to remove and install but doesn't leak anymore.

I gave up on locking gas caps since they never sealed properly and if you ever lose the key you play h@!! trying to remove it (done that).

[cdowns]

the one time i had an issue like that i got a new cascap and problem solved

[Rufton]

My Dad bought 1966 GMC cab tank truck in 1972. Still has OEM cap. Never noticed fuel coming out around RH turns. Top off and park on a hot day and expanding gas does spill out. Fuel does gush out while topping off if not careful. Don't know if OEM tank is baffled.