Fuel tank filler caps distorting

[Chevygold]

Here in the UK we have recently changed to E10 as the new standard petrol, E5 is still available but it is now the premium grade and a lot more expensive so generally I run on E10.
Last time I fuelled up I noticed the tank cap was a bit difficult to remove, on looking closer it appears that the plastic is swollen and the seal was in a bad way, these were new Stant locking caps fitted about a year ago, just wondering if anyone else had found this problem?
!976 Chevy C10 longbed with twin tanks.
Is there a metal cap available which might withstand the fumes of this awful E10 which we are forced to use and should it be vented or not?

Thanks
Graham

[VileZambonie]

Vented cap for your truck

[Chevygold]

Cheers Vile, are there any metal caps available that should withstand this E10 better?

[78 Chevyrado]

Here in the UK we have recently changed to E10 as the new standard petrol, E5 is still available but it is now the premium grade and a lot more expensive so generally I run on E10.
Last time I fuelled up I noticed the tank cap was a bit difficult to remove, on looking closer it appears that the plastic is swollen and the seal was in a bad way, these were new Stant locking caps fitted about a year ago, just wondering if anyone else had found this problem?
!976 Chevy C10 longbed with twin tanks.
Is there a metal cap available which might withstand the fumes of this awful E10 which we are forced to use and should it be vented or not?

Thanks
Graham

We run E10 here in the states.  Thats what my 78 C20 lives on.   I havent had any problems with my stant fuel caps.  maybe yours came from a bad batch?

[Chevygold]

Hi Kenny, bought as a matched pair keyed alike from Rockauto when I first got the truck a few years back before we went over to E10 here, no problems until recently when the caps both became a bit fiddly to get off and back on again as if the plastic body had swollen or distorted. Blamed the E10 as nothing else has changed.

Thanks
Graham

[78 Chevyrado]

Hi Kenny, bought as a matched pair keyed alike from Rockauto when I first got the truck a few years back before we went over to E10 here, no problems until recently when the caps both became a bit fiddly to get off and back on again as if the plastic body had swollen or distorted. Blamed the E10 as nothing else has changed.

Thanks
Graham

There's a possibility if they were built after Covid the quality of materials is lacking like most things these days.   I've had my pair for 10 year at least and no problems out of them.  they seal like new every time and no change in how they work or fit or seal.  They worked well when I drove the truck a lot and nowadays they still work well even though the truck sits 95% of the time. 

  Maybe find a vintage matched pair on ebay?  Pre Covid?       I dunno.

[Chevygold]

Thanks for your reply, I fear that the materials used may be inferior to the older items as you suggest, I'll keep looking for some that will fit, maybe with a metal body that will fit the filler pipe.

Graham

[78 Chevyrado]

Went way back in my ebay stuff.  I got my caps in 2017.  so I've had em 7 years not 10.    I bought Stant PN#17572  which is the keyed alike caps.   That PN is all keyed the same.   I bought two of them as you buy them singly but the same key fit both caps.

I did a cross search on rockauto and your 76 C10 takes the same gas cap my 78 C20 does.

old thread on here about it I found in my records..
http://forum.73-87chevytrucks.com/smforum/index.php?topic=35462.0

They Look like the one in the pic 1.  I painted mine silver over the red warning label part to look like pic 2.


Keep a look out for that part number on ebay and such and buy em when you can.  One at a time if need be.  It's one of those things it'll be there when it is and you got to snap it up when it shows up.

[78 Chevyrado]

Before I got the locking caps I bought a Gates PN#31743.    I had the stock fuel caps still so I only used the vent and new seal off the gates cap.   I reused my OEM outer cover and handle and had them painted to match the truck when it was painted.  The vent and seal swap right over.