My fuel tap won't turn completely off. The last time I tried to rebuild one, I couldn't get the cap threaded on without leaving the spring out, and without the spring it leaked. I've got the rubber seal ring on order. Is there a trick to getting the cap on?
https://shop.maxbmw.com/fiche/DiagramsMid/B0000398.png?v=09082020
https://shop.maxbmw.com/fiche/DiagramsMid/B0000398.png?v=09082020