Gas tank replacement

[mytoy]

Getting ready to replace my tank 67C10. What tank would you use for behind seat. And if I go to a tank for a 69 ,would that help vent the gas smell to a charcoal canaster. Thanks

[dmjlambert]

My truck is a 69 and doesn't have a charcoal canister. I think that was for later years. I replaced the tank and once I found a locking vented gas cap I liked and it seals well, there is no gas smell. A vented gas cap seals the tank shut, and only lets air in to replace the space gas occupied as it is being used. It will expel vapors only if under pressure, which rarely happens. If you switch to a later year tank and add a charcoal canister there are other things you also add, such as vent tubing, including a loop of tubing that goes up into the hollow space beside the back window on the passenger side, a tee on the PVC line, and a purge valve. Back in 71 and 72 the charcoal canisters had a built-in purge valve, but I believe modern more readily-available canisters do not have a purge valve and that is a separate thing. I don't think a charcoal canister would significantly reduce gas smell. Looking back and if doing this again, I wish I would have cleaned up and kept the original tank. I think it had a better lip that holds the gas cap on.

[mytoy]

Thanks for taking the time to answer me. I have tried many caps locking and un locking. I keep getting gas seeping out and running down the side of my truck. The filler neck is flat and smooth. It leaks with a full tank as well as 1/2 tank. I am aware the caps need to be vented. Thanks again for any help.

[dmjlambert]

I have seen posts here on the forum where people talk about getting some gasohol compatible rubber sheet material and add to or replace the old material in the sealing edge of the gas cap to beef up the sealing.

[mytoy]

Once again I Thank you for your advise. Will try to find the rubber you spoke of. I have an original cap that has a cracked gasket. Will give it a try.