O ring for clutch cover.

[gadget]

Today I've removed, cleaned and degreased my leaky clutch cover (as posted in 'what have you tinkered with today'), just thought I'd post my findings here as it might be a useful tip for others suffering the same oil leak problem. When refitting the rubber O ring I noticed it wasn't a nice snug fit in it's groove, it seemed it was about 2/3 the width of the groove! I've used a sealant to fill the groove prior to refitting the O ring and refitted the cover, not had a chance to test my work yet as it has to cure for 24hrs. I thought I'd search for alternative O ring materials on 'the bay' and found several sellers advertising Nitrile cord in all sorts of sizes so if my effort fails I'm going to give it a go with some Nitrile cord that fits nice and snug in the cover's groove hopefully negating the need for any kind of gasket goo. My thinking was ... if it's a snug fit it should be slightly thicker in diameter and so would have slightly more surface area to squish down on!?
Just thought it might help fellow sufferers.