I was out this morning and wound out the U-Turn at the top of a climb only for all the air to exit the fork. I wound the U-Turn back in, pumped up fork and headed home.

After some fettling and stripping/rebuilding I cant find anything obvious wrong but the fork will only hold air if the U-Turn is wound in, once it gets to near full travel all the air is released. Anybody any bright ideas about whats wrong?

You could have a scratch on the inside of your airtube (unlikely – I mean, how did it get there?), or your seals could be dry or perished. You need to do an airtube service – I’d do the whole fork. It’s not that hard. How old are they?

Send me an email and I’ll send you the RS service manual PDF.

charlieleppard(at)ymail(dot)com

Turned the U-Turn adjuster too-far, and turned/losened the valve with it? I know mine get a bit hissy (leaky) at the valve during compression if I accidently turn the U-Turn dial so much as one click too far. It goes if I wind it back.

Thanks for the ideas. After some more fettling it looks like the snap ring that retains the +ve valve in the air chamber has somehow came off allowing the valve to pull out of the chamber at the end of the U-Turn stroke. Looks like I do need to do an air chamber service to get inside and put it back on.