thirsty

I have heard this from another 1960 corvette owner and it prompted me to write a post.
If I fill up my 1961 Vette to the top, I can smell fuel fumes for quite a while while driving.
If I fill it 3/4 or 1/2, no probs.
After the first time I actually pulled over and checked the carbies and fuel line.The second time it happend was this weekend and I clicked it is only when I fill it to the top.
The filling cap is of course on the panel right next to drivers side on the left. Fuel will be moving back and forth in the tank.
I notice fuel is sometimes at the bottom of the fuek tank filling point when I go to fill up, like its split but the cap is tight.
The fuel caps are a breathing set up, but why am I getting such fumes when full?
Why is it leaking out as when I check the fuel cap its tight?
Lastly, there is a small rubber open hose above the fuel cap. I suspect its a breather, but whats it for exactly?
Would the fuel cap need replacing or do I need to lift the soft top and get access to the fuel tank and make some mods?

wmf62

the C1 uses a non-vented cap and the hose is the vent line for the tank.

if you fill the tank to the top, the gasoline will expand and overflow out the vent line.

solution, don't fill the tank to the top.
Bill

Frankie the Fink

If you top off the tank completely you can actually make raw gas run out the long rubber vent tube that goes to the filler gas cap cavity. I can produce the gas smell on demand by making hard right turns (particularly uphill) with a brimming tank. It's normal but avoidable if you don't top off the tank.

JohnZ

Read this - it shows all the causes, and the fixes.

http://www.lbfun.com/warehouse/tech_...hnHinckley.pdf

thirsty

Great Help again guys.
Please forgive me for my knowledge on the light side on C1's.

I have had Mustangs all of my life. This is my first Chevy buy.

The article was spot on and.... I have a vented fuel cap - Will get this changed right away.

Kind Regards,
John

wmf62

i also use a vented cap and i don't attribute any gas smell to that alone; it is entirely caused by me topping off the tank till the filler neck is full and the gas coming out the vent hose and/or the cap.... if i don't fill that high, no smell...
Bill

thirsty

Agreed,

I am "learning" the car at the moment.

dharris45

Not to hijack this thread, but where can you buy non vented caps. I have one of the very expensive Stant reproductions that I will use for judging, etc. But I don't want to leave it on the car. The only ones that Paragon or Corvette Central advertise for my 1960 are vented.

Don

62Jeff

Got mine at Autozone. Any auto parts store ought to be able to order one for you if they don't have it in stock. John's linked article has the part numbers.

wmf62

Jeff
the Autozone site shows that 10810 part # (actually the CST 6810) as a vented cap...

http://www.autozone.com/autozone/par...fier=4367_0_0_

Stant shows it to look like this

http://www.stant.com/modules/partLoc...m.cfm?id=10810

Bill

62Jeff

Interesting. When I bought my cap, I gave them the number Frankie posted a few years ago. Today it was easier to cite JohnZ's article above.

wmf62

this is the pic on the Advance site

http://shop.advanceautoparts.com/web...archTerm=10810

definitely wrong...

Bill

Frankie the Fink

NAPA #703-1205 cap works great on C1s.

dharris45

Frankie,

I can't find this number on NAPA's website?

Kerrmudgeon

Thanks John, great article.
Does anyone have pics of the grommet and drain hose that goes under the body, mine is missing.
I learned many years ago not to fill my 62 completely by the way.

Frankie the Fink

Wow - neither can I ! NAPA must not have had enough demand to continue carrying it...it isn't even listed on the STANT (the OEM cap manufacturer) web site any more.

Go with the STANT 10810 per the John Hinkley article and that is listed as a direct replacement for the #703-1205 cap...should work perfectly.

UPDATE:
Well now it looks like the STANT 11810 replaces the 10810...my head is starting to hurt.
NAPA #703-1684.

When you use STANT's online vehicle selection search it says 10640 gas cap. This last one has the label on it about venting and anti-surge; so I would NOT use the 10640.

You want NON-vented cap!

dharris45

I just got back from NAPA, I bought a 703-1684, their computer show that as a replacement for the 703-1205 you referenced earlier. It is definitely vented, not sure why I even bought it

Their computer showed another one compatable with the 1960, part number 703-1033 and it is also vented.

If you look on Stant's web site and search for the 11810, it comes up as part number 10810, which also is cross referenced as NAPA 703-1684, which is Vented - My head is spinning also.

I just sent an Email to Stant to see if they make a Non-vented cap for the 1960 corvette. Paragon has one listed for 57-58 (equal to GM part number 3751027) which I assume should be Non-vented and that GM number is listed in my 1960 AIM as one of three gas cap part numbers, so it should work for my 60. Their price for this cap is $37 and I spent all of $5 for the Vented one I bought at NAPA.

I'm going to send an Email to Paragon to see if they can tell me if that one is Non-Vented.

Frankie the Fink

How did you determine that ?

I also emailed STANT asking them about non-vented caps for C1 Corvettes - let you know what they come back with (if they do!).

I haven't looked at all the vendor's gas caps for C1s - but the 2-3 that I HAVE looked at were ALL wrong and VENTED....which is why I wound up at NAPA in the first place a few years back.

Paragon's shows "ANTI-SURGE" and "VENTED" right on it. It is WRONG.

wmf62

just look at it... it has a check ball in it

if you look at my links, every site i looked at showed the 703-1205 as a picture of a vented cap of some sort
Bill

Frankie the Fink

Neither of your links shows a 703-1205.

After diddling in cyberspace I am becoming convinced that this STANT cap may be "The One"! (it is listed as "sealed") -