A bit of background...
My 08 U-Turn Reba Team (air) were fitted to my old bike and as they always weeped a bit of oil from the top cap of the u-turn adjuster when on their side or upside down in the car, I started putting the bike upright in the car & rarely storing it upside down in the shed.
I recently swapped them over to my new Inbred frame & rode the bike for the first time last Thurs. After the ride I put the bike upside down in the shed without thinking.
On Sunday, I went in their & found a pool of oil under the spring side of the fork and the u-turn adjuster was covered. So, I assume it is most of the 15ml of fork oil put in the lower to lubricate that leg....?? Is that correct?
And if so, how does it get out of the u-turn adjuster seal?
The u-turn adjuster top cap goes down into the stanchion tube, which itself is sealed at the other end by the various internal gubbins. The lubricating oil is squirted into the lowers & should slosh around in there, shouldn't it? If it comes out of anywhere, shouldn't it be the wiper seal between the lowers & stanchion?
I am guessing that it leaked in the first place as it hasn't been upside down for so long the o-ring dried right out. But, when it's leaked before it's only been a wetting of oil, not the a massive puddle of it!
I'm probably just gonna squirt a bit of oil into the lowers & see how it goes from there, until i can give it a proper service. I would replace all the o-rings but after buying a TFT Tuned service kit & finding the o-rings I intended to replace didn't seem to be in there, I don't really wanto to spend £30 on a service kit that doesn't contain the correct bits. Do SRAM do service kits?
I serviced my 2006 Rebas by buying an O ring assortment (I think from B&Q), and some circlips/eclips from a motor parts shop. Check that the kit you buy has the sizes you need, or even maybe buy them individually off ebay?
That was over a year ago, they have been fine ever since. Might do them again soon...
Incidentally, maybe newer ones are different but on mine the U turn adjuster is on the air leg, the other leg is the MoCo. Are they losing any air?
So, I assume it is most of the 15ml of fork oil put in the lower to lubricate that leg....?? Is that correct?
No. If it's coming from the top cap (NOT from the seal area) it's lubrication from inside the air spring. Partial strip down required to replace it. Not hard though.....
If it is then [i]"I'm probably just gonna squirt a bit of oil into the lowers & see how it goes from there"[/i] won't work.
tomhughes46 - yeah I would buy individual o-rings or an assortment, but don't wanna take fork apart to measure required parts, then have to trundle off to get them. A service kit would be ideal, but reluctant to buy another one.
Yeah - u-turn adjuster in on the air side, as in (air) spring in my post above.
I don't think they are losing air - hard to know definitively as they lose so much when you connect a pump, but the 'feel'/sag etc hasn't changed.
PP - NO!! I was worried you were going to say that. It doesn't look difficult, but does seem to be quite fiddly.
There was quite a bit of oil on the floor - I thought the quantity of oil in the air spring assembly was only 6ml.....which is little more than a teaspoon full. They still seem to be holding air at the moment.
They still seem to be holding air at the moment.
Thinking about it, I might be wrong. I just can't visualise the inside of a U-turn Reba right now to work out if it's possible the lower leg oil could come up past the u-turn cartridge..... 😕
Looking at the tech manual just now - it looks like the air cartridge (for want of a better word) screws into the u-turn top cap at one end and the other end (the long plunger shaft) is secured into the bottom of the lower leg through the hole (with a nut).
In between this is the actual cartridge assembly and this seems to fit somewhat loosely within the stanchion; there appears to be no o-ring or similar holding it into the stanchion.
I was thinking that the air cartridge was well sealed into the stanchion, but it's the seals/plates around the bottom of the actual air cartridge that I was thinking of. It looks to me that the lower leg oil is free to move all around the lowers & up into the stanchion between the stanchion wall & the outside of the air cartridge.
And I reckon the oil has leaked out of the seal where the valve comes through the centre of the u-turn knob, rather than around the threads of the u-turn knob assembly......which would imply it's the lubrication oil.
Sounds plausible? It was quite thick oil (the air assy oil is 5wt, lube oil is 15wt).....