Feinwerkbau 700 air cylinder

[NovaNewfie]

So I finally remembered to take my spare air cylinders to my daughter's practice so I could fill them with a tank and check for leaks.
Turns out three of them were leaking. 2 were blowing right out through the valve on the end. I got lucky on the first one and it sealed up first try with a random oring out of a kit.
2nd one took five attempts to get it to hold air at 200 bar. After 4 hours it dropped about 10 bar.
Does anyone happen to know what size oring it's supposed to take? Feinwerkbau say "do not open" the air cylinder so I can't find any specs for the oring.
Cibles said they could send them to me for I think it was $6 or $10 each plus shipping. Not that I'm being cheap but it just looks like an oring I could likely get at any hydraulic shop.

[Daryl]

Princess Auto has O rings in kits. I bought the one in the orangy box. There are a multitiude of sizes & 407 O rings in the box.
From ID 1/8" to OD 1/4", up to ID 2" OD 2 1/2" & at least 10 of each size. I don't remember what it cost - maybe 20 bucks of so.
They also a metric "kit". I was able to use this kit to re-seal a couple of Gord's Air Force Talons as well as the intake seal on the Bam 51 I had.

[NovaNewfie]

Princess Auto has O rings in kits. I bought the one in the orangy box. There are a multitiude of sizes & 407 O rings in the box.
From ID 1/8" to OD 1/4", up to ID 2" OD 2 1/2" & at least 10 of each size. I don't remember what it cost - maybe 20 bucks of so.
They also a metric "kit". I was able to use this kit to re-seal a couple of Gord's Air Force Talons as well as the intake seal on the Bam 51 I had.

I have 8 different kits in SAE and Metric. I believe the oring may be an oddball size like some of the other stuff from Europe. What fits close is a 5 x 9 x 2 mm. I expect the original size is likely closer to 5 x 10 x 2.5.

[ineedpal]

If you find an oring that roughly fits then you should be fine. I never have problem using orings of slightly different sizes.

[Gippeto]

Would measure the parts and give Hitech seals a call.

https://www.hitechseals.com/contact.asp?lang=

[NovaNewfie]

Would measure the parts and give Hitech seals a call.

https://www.hitechseals.com/contact.asp?lang=

I ordered a few new ones from Cibles for my cylinders, as well as a new cylinder for my daughter for competition.
When I get the new ones I'll measure them and see what I come up with.

[NovaNewfie]

Based on my measurements this seems to be the seal I need.