I have a set of 2012 F120 FIT RLC's that annoyingly are just beyond their 1 year warranty. They lead an easy life on my full suss bike (I have an older hardtail for grimy stuff and given the way last summer/autumn was, that has been used a lot!). I thought I would give them a basic legs off/new oil/new stanchion seals service as I had not done it at the crazy 15hrs suggestion. I was also a bit worried that the forks had started to feel much stiffer despite air pressure being fine, and had minimal sag. They felt nothing like the Pace and DT Swiss forks I have used before.
Anyway, the damper side leg had plenty of nice clean (still green!) oil in it. The air chamber side had very little. I put 30ml in each side and rebuilt them but annoyingly then saw some stuff on the interweb about oil getting into the air chanmber sometimes, so ordered the 26mm flat socket from Mojo. Sure enough, there is about the same amount of green oil in the air chamber as came out the damper side leg. It was swimming in it, nothing like just the 5ml of float fluid supposed to be in there.
I ordered some new air seals and the wiper seal that sits below it inside the air-side leg (I think the latter is now a rubber improvement over the old foam one). I am pretty peed off as a) this is not great on a £750 fork used so lightly they looked like new inside and b) I now need to strip them again and throw away the new oil I just put in there to try and change the wiper/air seals. If your Fox forks feel a bit odd, try letting the pressure out and taking the air-side top cap off to see if there is loads of oil in the air chamber!
Question though: Oil in the air chamber seems reasonably, if not very, common from interweb searches - on every thread I have found about it, some wag says "did you store the bike upside down?". In all the threads I have seen about it, the person with this issue did not. However, I do, and wonder if anyone knows (beyond speculation) that this can make this problem occur. Fox themselves suggest to store the damn things upside down! But then they want the same money for an mtb fork that needs servicing every 15 or 30 hours as would buy a good set of shocks for my car that would last 6 years/100k miles + with no work, so they obviously have a sense of humour I fail to understand.
Change the foam ring for a scraper seal on the air piston and it'll sort the issue.
Cheers - I have one ready to go in. Wish I had known about this before I put the legs back on!
Bit nervous about continuing to store the bike upside down though...
If the old foam scrapers were so bad and this issue can happen so quickly I wonder why everyone with Fox has not had the same issue. It was pretty obvious how un-plush they felt. Maybe most people just send them back to Mojo, Mojo change the scraper when they find the chamber full of oil, and the owner is none the wiser there was ever an issue and thinks "they feel great for a service" when they didn't need a service - they needed a defective part changing.