Got a set on a hardtail which is sitting on a turbo trainer. Decided to rake bike for a ride and fork has no air in it, so I started pumping air in and I heard a hiss. Coming from the grease nipple.
Any ideas how I stop the escaping air? Bike hasn't been used properly for about 10 months, so hasn't been greased, but whilst it was used the fork got a squire of grease each week.
How do I reset the nipple to make sure it seals/seats properly?
Ta.
Im not specifically familiar with the forks, but the grease nipple won't access the air spring I would have thought. It would be for the bushes/seals.
So if its leaking air from the nipple thats because its changing air pressure inside the fork legs. Thats either because its now a vacuum as you pumped the forks and they extended, which is not an issue, or its the air spring leaking into the leg, which is.
Have you tried greasing via the grease nipple?
As above, the grease nipple will not be designed as an air-seal. Air is getting in, or leaking out, of somewhere else!
They're old Paces. They'll be leaking internally.
Yes, I'm still scarred from my RC37 experience.
Definitely from the nipple...I can feel air escaping and if I put finger over nipple, it stops and pressure appears to hold.
Will grease again. The design is indeed 20 years old so apart from the wiper seal and an o-ring the inside of the leg is open so nipple is 'inside' air chamber.
My guess is that the air spring is leaking air into the fork lowers which is in turn leaking from the grease nipple.
Having taken them apart the leg with the air in it is literally just that...a valve in the bottom of the lower stanchion, an o-ring and wiper seal at top of stanchion (with a wee hole where grease nipple would squirt grease) and then the upper leg goes in. Suspect there is some damper in the upper leg, but definitely an issue with lower. I'll give Fork English a shout and see what he can suggest as I can't work out why (or what has failed) as everything appears to be in order and in shape.
I hadn’t read your second post before posting. You could probably get away with replacing the grease nipple, though. Assuming it is replaceable.
https://drive.google.com/file/d/0BzmF6AisSYM1UnRVRllweXRrZ1U/view
I thought, and according to the pace drawing above, that the RC36 evo 3 was a spring in one leg and air assist/damper in the other. It wasnt until the air force models that they went sans spring...
Anyway, most likely you've got a bit of dirt lodged in the grease nipple, keeping it slightly open.
Strip the fork and go over the inside of the nipple with a toothbrush, give it a blast with compressed air if you have it. refit and regrease.
Regreased nipple and a pillow mank came back out...pumped fork up and no air loss and after 4 hours still inflated - previously they were soft in a half hour.
Thanks for suggestions, will give forks a strip and clean at some point in the next few months. Hopefully it'll be sorted now.
