Fitting the seal on the fuel filler cap

[Philip Wardle]

I have struggled for an hour or so without success, my hands lack strength and dexteriy so I will need help - meantime just wondering if anyone has tips to make the job easier?

[APS]

Warm it up, either leave it in the sun for an hour or use hot air gun. Use some soapy water on the seal as well, put a cloth in opening to petrol tank, if trying to fit it whilst on the car.

[Philip Wardle]

Thanks for that, we'll try again as you suggest

[gbb483]

I fitted mine OK, but the rod that the lock locates on kept flipping it off again. I had to shave a flat on the seal on the side that fouls the rod.

[Tdafforn]

I fitted mine OK, but the rod that the lock locates on kept flipping it off again. I had to shave a flat on the seal on the side that fouls the rod.

Also had to do this. But works fine once fettled.

[Teldbin12]

I changed mine recently together with the fuel neck was was also tight, I use a little silicon spray to help it

[Philip Wardle]

Just to complete this story, the reason I couldn't fit the seal is that the re-chromed filler cap assembly I bought may years ago, probably at a car show or autojumble before online was even a thing had the wrong part fitted - first picture below shows the wrong part on the left, the right part is shown one on the right with seal fitted.

I managed to swap these over, the means of fixing is a 1/16 inch roll pin which I believe to have been 11/16 inch long originally, though 3/4 inch length is more readily available and fits well. Goodness knows where the plastic part came from, but it surely wasn't a Stag. Second picture show everything in place and working just fine.

IMG_4699.jpg



IMG_4701.jpg

[Paulfrazer]

I find that the neck if the filler cuts into the seal after only a few months. Does anyone know the source of a seal that would last rather longer?

[Philip Wardle]

I don't have an answer Paul, but I can already see a witness mark on my seal after a few days. Ho hum.

[Paulfrazer]

Hmm. The pressure plunger thing on the cap doesn't line up properly with the filler neck on mine which doesn't help. There doesn't seem to be any way of adjusting it though. I am sure that attempting to bend it would end in disaster!

[Philip Wardle]

Your're right, the witness mark on mine is off centre. I can't see any way to adjust either! Grrr

[Paulfrazer]

Here is a photograph of the latest one off mine. I can't imagine that they were always like this

Edit - I wonder whether filing the sharp edge off the filler neck would stop it from cutting the rubber so much

Edit ii - I have just tried spraying the rubber with silicone spray in the hope that it might slip into position a little easier. Time will tell!

[Philip Wardle]

Interesting ... it might be my imagination, but the spring on an original (rather corroded) cap in the shed feels a bit less strong than the nicely chromed one on the car. If I can confirm this a bit more scientifically I might look to see if I can swap the springs.

[Paulfrazer]

My cap assembly looks original but the spring is quite strong. I wonder whether anyone else has this problem

[Paulfrazer]

Just an update on the state of my filler cap seal. Looking at my records I bought it in May 2024 and probably fitted it soon after. It looked different to the ones I had fitted previously and on checking it this morning there is a circular line where it connects with the filler but it is not at all cut unlike the others I have fitted. Unfortunately I don't know where I bought it from! The entry on my bank statement for th edate I bought it shows "Eagle Rubber" but I am pretty sure I bought it from one of the usual sellers. It wasn't ebay.

Doing some research I have found nitrile rubber seals which I think mine must be. It was thinner and more dense than the usual rubber ones so I am assuming that is what it is. Worth looking for when replacing them. I also sprayed it with silicone spray after I had fitted it but I don't know whether that made any difference.

Edit. I think this is the one I bought https://coh-baines.co.uk/products/st...cap-fuel-cap02