Fuel cap rusting onto filler neck

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purplepeter
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Fuel cap rusting onto filler neck

Post by purplepeter » 10th April 2020 - 7:48pm

A bit of a strange one.. My filler cap has started rusting itself onto the filler neck inbetween fill ups
Obviously I'm inclined to give it a finger full of grease, but the question is.. What kind of grease do you reckon? Lithium, silicon, copper, moly or red rubber grease?
Any opinions please?

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broady_6
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Re: Fuel cap rusting onto filler neck

Post by broady_6 » 11th April 2020 - 9:41pm

Id go with copper or graphite any seize type. I expect itll need regular replacement as the fuel will wash it away. Interesting issue that I shall ponder
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937carrera
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Re: Fuel cap rusting onto filler neck

Post by 937carrera » 12th April 2020 - 9:20pm

I wouldn't go for copper, never sure where all those particles will end up, especially on a FI engine.

I have seen this a couple of times, I think I just put some engine oil on the filler cap and neck and rubbed it in. Massage for your fuel filler :)
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

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purplepeter
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Re: Fuel cap rusting onto filler neck

Post by purplepeter » 12th April 2020 - 10:22pm

Ahaa... Engine oil.. Good call!
It appears to be just rusty at the very top edge of the filler neck where it seals against the rubber seal, though I might suspect the threads of the cap need a clean too.. will give it a go

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Rob 400e
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Re: Fuel cap rusting onto filler neck

Post by Rob 400e » 13th April 2020 - 9:59am

While we are on the subject my filler tends to leak slightly on a full tank, I assume it’s the rubber seal. Does anybody have a good one for sale?
Type 411 Le four door auto .
1965 Beetle

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purplepeter
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Re: Fuel cap rusting onto filler neck

Post by purplepeter » 13th April 2020 - 10:06am

Perforations in the steel filler neck are fairly common, which can be brazed up. Also check the J shaped vent pipe
I'd have thought a Beetle filler cap seal would fit

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Rob 400e
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Re: Fuel cap rusting onto filler neck

Post by Rob 400e » 13th April 2020 - 11:10am

Cheers will add it to the growing list of jobs to do!
Type 411 Le four door auto .
1965 Beetle

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