Should I replace vent lines?

[71super402]

Hi folks, I just picked up a 72 that's been sitting for two years and there is some rust on the gas tank, so I have decided to buy a new one and replace all fuel lines and the fuel pump. It is the original EEC setup so should I replace the vent lines on the left upper side of the tank, or since those lines don't get actual gas through them is it ok to leave those as is? Thanks!

[Steeveedee]

The lines could crack and vapors could stink up your cab. If it were mine, I'd do it. If you don't care about originality, you can remove the system, cap the vent line at the tank (or buy a tank without that nipple) and use a vented cap.

ETA- I was a smog mechanic up until '83 when I graduated uni. I can't believe that I'm giving recommendations on possibly bypassing emission controls.

[jumpsoffrock]

You should read up on all the bad reputation that some aftermarket gas tanks get as far as fitment is concerned. The last thread I saw had several complainants.

[Palf70Step]

Originally Posted by Steeveedee

The lines could crack and vapors could stink up your cab. If it were mine, I'd do it. If you don't care about originality, you can remove the system, cap the vent line at the tank (or buy a tank without that nipple) and use a vented cap.

[71super402]

Thanks for the replies much appreciated.

Steeveedee, so should I replace the metal line along with the rubber connection, or were you just talking about replacing the rubber parts of the venting system? By the way, I am definitely keeping the EEC system and restoring it.

Jumpsoffrock, as far as the tank goes, it's really pretty rusty so it seems like if I cleaned it, I'd just have the problem again in the future. Not sure if I have a choice but to replace it?

[Accelo]

I can recommend these guys. Quanta
https://www.gastanks.com/1970-72-Che...ctinfo/GM-49B/
The Corvette tanks I purchased were perfect.
Rising Sun, MD 21911
sales@quantaproducts.com
The tank is available with our without ECC.

Chevrolet Pickup Truck: 1970-72 w/ E.E.C.
GMC Pickup Truck: 1970-72 w/ E.E.C.
$229.

The lines that flow fuel are easy enough to replace. Some of the vent lines are built into the cab and go over the rear window.
Leave them alone, like you would have a choice.

Cheers

[sick472]

You said rust "on" the tank...Pull the sending unit out and check out the inside for rust. I just pulled a tank off a 67 car and it was pretty rusty on the outside, no bad pitting, but the inside was beautiful. This could save you the cost and headaches some experience with aftermarket tanks. If the rust "on" the outside is pitted, it may be time to get a new one. Pits can go at any time and that would not be good with a fuel tank.

As far a the rubber lines on the tank...if you are not comfortable looking at them and determining their health, just replace them. Questionable lines will show micro cracks when bent back and forth and/or the outer surface will flake or scarp away easily with a fingernail. Easy to replace and cheep at any rate.

The steel vent line that goes up into the cab should be in fine condition since it is protected from the elements. Check it by flexing it gently throughout its length and look for areas that may tend to kink easily under light stress. These areas my be rusting through from the inside (doubtful). That piece can be remade from some steel tubing pretty quickly if you question its integrity..

[Steeveedee]

Originally Posted by 71super402

Thanks for the replies much appreciated.

Steeveedee, so should I replace the metal line along with the rubber connection, or were you just talking about replacing the rubber parts of the venting system? By the way, I am definitely keeping the EEC system and restoring it.

Jumpsoffrock, as far as the tank goes, it's really pretty rusty so it seems like if I cleaned it, I'd just have the problem again in the future. Not sure if I have a choice but to replace it?

I was just thinking of the rubber parts. If the inside of the cab isn't rusted, the steel vent lines would be fine.

Just so you know, there is a replaceable filter in the bottom of the vapor canister.

[72SB]

My 72 had tank replaced, vented, by PO and new soft lines to the hard lines on frame. There was also a fuel filter on the frame line soft line which is wrong, so I removed it and put a inline filter between FP & carb. I replaced all the old cracked vacuum lines going to EVAP can on PS front fender. No gas smell in cabin. IDK what brand gas tank but I have no issues with it. YMMV

As mentioned, check inside of tank for its condition, it may be fine. I have a borescope I bought on Amazon for around $30 which comes in handy for looking in things

[71super402]

Thanks for all of the replies. I will take a look inside of the tank and make sure there is no pitting on the outside. Replacing all the rubber seems like the thing to do in regarding the vent lines.