Hi all, last time I filled 'er up (just before the lockdown started..) I noticed this gasket has kinda melted and come away:



I'm guessing this is also related to the distinct aroma of petrol that hangs under the bike cover on warm days. So, first off, I guess I need the most expensive seal set here because it's the only one that seems to have this seal in it. Secondly, does anyone know if I can buy that part separately? And thirdly, can I buy one from somewhere that isn't going to melt when it comes into contact with fuel??

Cheers all!

Lucky you the seal on mine has turned to stalactite like rock very near impossible
to remove without damage to the seating lip.Buy the BMW kit or just make your own using good cork gasket and sticky stuff to seal it   dont know anyone that 
just supplies it on its own

Petrol Tank Cap Gasket 16111456007

Gasket set Fuel Tank BMW 16119062461 Tills.de

Thanks both, the expensive kit it is then..

The gasket appears to be neoprene which I would expect to melt if left in contact with petrol, but if others haven't had the issue then maybe it's a one off??

Snod Blatter wrote:Thanks both, the expensive kit it is then..

The gasket appears to be neoprene which I would expect to melt if left in contact with petrol, but if others haven't had the issue then maybe it's a one off??

It's likely to be made of Viton, a synthetic rubber that is fuel- and heat-resistant.

I managed to soften one up by soaking it in Oil of Wintergreen for a couple of weeks. However once removed it hardened back up.
Regards Martin.

Are you all looking at the one that actually does the sealing? I'm talking about the one at the back which has definitely not gone hard, more gone floppy!

Snod Blatter wrote:Are you all looking at the one that actually does the sealing?

I think they all do sealing for one purpose or another. The "back" one seems to supply tension and cushioning to the cap in addition to any sealing duties it might provide.

Your assembly has corrosion to an extent that makes me wonder if the water drain line and the vapor line are plugged.

Ahhh is that what it does? I was hoping it would make more sense once I took it to bits. I guess that helps explain why they all come as a set.

Fair shout about the drain hole being blocked, I did have an occasion where I opened the cap and a load of water fell into the tank! I just brimmed her and went home.. Seemingly none the worse for it. It's always looked like that while I've owned it though, thought it seemed normal enough.

Petrol Tank Cap Gasket 16111456007 is made of rubber cellulose material a medium/high density neoprene.

If that's the original cap gasket you got your moneys worth.

Service Bulletin 2196 February 1986

Regards Martin. probably referring to Fuel tank GASKET RING 16111453690 K75 - K1100LT scented with Oil of Wintergreen

Try a lengthy soak in 303 Aerospace Protectant to renew plasticity in rubber. It will never be new again but may become serviceable.

FYI: Rub the Oil of Wintergreen on the chest to kill the COVID-19

Something to try when attempting to revive rubber bits - Gummi-Pflege.

Funny sounding name but it seems to work. First brought to my attention by our now sadly departed member MikeP.

Read post 131 in the following thread.
Will I never learn

Cheers

Gummi-Pflege  82149407015  no luck not available from the MaxBMW fiche

worthwhile alternates

Genuine Honda 08798-9013 Silicone Grease
rejuvenate rubber seals, lubricating door seals, window channels, sunroof seals

Genuine Honda 08798-9002 Hi Temp Urea Grease
metal-to-metal contact