Avgas Leak at Cap Lock Tumbler




I have searched to no avail for someone who has this same issue.

The 2015 SR20 that I fly Currently has 1300hrs, and maintains a tail to spinner warranty. The problem with my fuel cap leak developed around 1200. BOTH caps decided it was time to spew avgas from the cap through their little lock mechanism (about’ as fast as a can of spray paint out the wing). Cirrus has been very helpful, and warranty came through, covering the expense of a ‘fuel cap overhaul’ during the incident at 1200hrs immediately after the problem developed.

Fast forward to yesterday, The right cap decided it was time to trickle blue fuel through the cap lock seal, making it apparent that the cap is again -compromised (just 100hours after overhaul??). The new ‘leak’ is not as extensive as before. My Cirrus shop has been notified, and they take good care of us… I was to;ld to expect warranty to give me new caps. The Shop has “Never seen this issue before!”

I was told by my buddy to join COPA and ask wise counsel. Has anyone here have any experience with this issue? Is there something i’m doing wrong here?

Thank you for your time…


I have seen it before. There is a small oring in the tumbler that can leak. Cirrus has a rebuild kit that has all the oring in it and and OH it. A second leak mode is the nut on the bottom may need tightened. In your case it appears it is the tumbler oring.

It is pretty straightforward and it is pretty much impossible for you to be messing it up. I would hunk you’ve just gotten some poor (or poorly installed) oring.

Good luck.

Mine is 2003 and sprays the same way. Overhauling didn’t change a thing.
I fuel one finger wide less and make slow climbs, please no comment on the 20’s climbing performance :/)))

You can also get the rebuild kits from the manufacturer (name escapes me right now but they’re British) and IIRC Aircraft Spruce as well. Ah, Newton Engineering is the name…

I would assume Cirrus would be a much more expensive source, simply because they are for everything else.

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Interesting. The oring is easy to tear when being installed. Your might try again.

Yes, the Cirrus markup is quite a bit more than ACS.


They have to change all the seals…




Obligatory seal reference. This is required by the internet.

That’s Hilarious!

Thankyou for all the advice, suggestions and the link to aircraft spruce. Using that part number for the overhaul kit, I was able to track two down at my local supply Aero Performance. With the help of my neighbor we carefully installed the new o ring. Back to the air tomorrow in order to see if the problem still exists!!

Keep us posted

I’m having similar issues from the cap on my right wing. Had someone tighten up the nut on the bottom and no improvement. For my '03 SR22 will I need the same A300 kit?


yes, probably those small oring that seal the tumbler is in need of replacement.

Trip, a classic that never gets old!