I noticed some venting through one of my caps. I ordered both the large and small O-rings.
However the bottom plate on my cap does not turn to tighten. Its basically loose on the shaft. It’s not threaded and it appears the only way to tighten is via tightening the lock nut on the bottom.
I’m assuming that’s the way to tighten but thought so would ask before I head back up to the airport with the new O-rings.
That’s the diagram I referred to when ordering the o-rings. However when I removed the locknut on the bottom the lower washer plate just comes off. It does not seem to be threaded.
Incidentally the cap on the left wing looks like the diagram but the right wing is slightly different. The lower washer plate is “thinner” on the right wing
Im thinking I might have a different cap on the right wing.
The o-ring is damaged and has a nick but it seems to be the same as I received.
I’ll head back to the airport and pull the cap completely apart and see what I have.
If I recall correctly, my caps just have the nyloc nut on the bottom. Put on the new O-rings and tighten them a little at a time until the cap wont turn in the fuel neck when the locking tab is down. They should remove freely when the tab is up. If you tighten too much, you will knw, because it will require some wiggling to remove the cap with the locking tab up.
I think that’s the way the cap in the right wing works. The one in the left wing is different and looks like the picture posted earlier. I’ll go up and put the new o ring on but I suspect I will buy a new cap just so they match.
IIRC, the older Usher caps just had a Nyloc nut to adjust the amount of closure. The newer ones have a second threaded fitting so you can tighten them together after adjusting, for a more secure lock.
Fuel Cap O-Rings
Linear Mode
