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Bought a pair of 2010 SL's which have had about a years of use. Noticed the travel was down from 140 to 130 but letting the air out put them back to full travel. Previous owner seemed to be running 155 (-) 150 (+). Also noticed the valve's were leaking a fair bit of oil - more than i'm used to with my Reba's.
Went for the first ride and all's good. Decided to play around with sag as was not using near full travel. Took all the air out of the negative and a fair amount of oil was leaking out of the valve. Took all the air out of the positive, then reinflated positive, then negative, both with less air. Forks were not sagging without a push. Got to the bottom of the run and even less travel was used.
Again, went to deflate the negative chamber and no air voluime was registering. Took the positve air out, reinflated,then on taking the shock off all the air was escaping out the valve. I also noticed a few shards of black plastic/rubber in the positive valve. The negative seemed to inflate ok.
Any ideas before i take them apart?
I'm guessing the black plastic is a knackered O-ring and it might be jamming the valve.
Do the valve cores come out using the usual car tyre valve core remover?
tbh I would just get em apart and stop messing before anything gets damaged further. Evilhomersimpson on ebay sells O-ring kits for most Rockshox forks.
Bumpty.
Taken forks apart. Lowers were full of dirty gritty lube oil so a good clean there and some new foam rings.
Taken dual air apart and from what i can gather does not seem to be anything visually wrong with the components.
Finally fished out some sizable bits of grits out of the positive valve and gunk out of the negative valve so perhaps this was causing the problem.
Is it worth replacing the O rings? Also do you use ( red rubber) grease as suggested by Rockshox on the rings, or just chuck in some suspension fluid (5wt?), or both?
If you've got O rings (or obviously if they need replacing) you may as well replace them. Go lightly with the grease, and again as you may as well replace the damping oil, but get the volume correct (130ml? the manual will say)
Some fluid out of the negative chamber on deflation is normal, not to be stressed. If it's black and gunky an lowers oil change is in order.
If you're not getting full travel with the chambers balanced, or the bike is not sagging properly I would change the air spring o-rings. At the very least, remove them carefully, clean them with IPL and replace them greased. Remember to clean the inside of the stanchions and lowers with IPL and a rag on a pointy thing.
Remove the schraeder valve with a core remover and clean and grease it and reinstall.
Sram grease isn't castrol red rubber grease, it's "Red Rum" which is, afaik, just like float fluid; a very high viscosity suspension oil. 5wt is too fine and will quickly remove itself.
Lowers back on, but don't push them down yet; turn on side, squeeze in 6-8ml 15wt into them, then push together and do the bolts up.
However, if you aren't getting full travel irrelevant of the air pressure (say, still at 50psi in each chamber), it may be hydraulic lock from the damping side. Open it a bit, compress the fork totally and close it again for a quick fix.
Thanks for the advice - purchased a complete service kit. I use (expensive) red rum to lube the foam rings so that's good. Can I pick up a valve core removal tool from somewhere like Halfords?
yup. Any motor place will have one, maybe even your petrol station.
I use Standec grease on my seals as I prefer a grease as it acts a a nice dynamic seal as well as reducing stiction and damage during assembly. It is silicone based so doesnt mix with the mineral oil used in the fork and get washed out.
Come to think of it I was given some of that judy butter - that seems like good stuff and presume will do?
Rebuilt the forks, everything apart form the valve cores. Inflated and everything ok, deflated and the second time the air pissed out of the positive valve again. Will replace valve cores tomorrow and if that doesn't work, i'm stuck 😕
And now the compression lock off isn't working now, even after playing around with the floodgate. I measured the fluid as best i could in a 20ml syringe and def put in 123ml.
Help!
Replaced the positive valve core, and i think that was the sourse of all the problems, although damper lock off still not working.
However, now when inflating the positive, then negative followed by deflating negative then positive, and repeating, the negative seems to have about 50psi on reinflating after the positive! Also the forks are not showing the full 140mm travel when i'm not sitting on the bike although putting more air in seems to help. On reattaching the pump the reading are about 10psi less as expected.
So, is air escaping from the posiitve to the negative (although the readings don't suggest this) or do the forks take a while to bed in or is the travel effected by the amount of lube/grease on the dust seals i put in the lowers?
Sounds like you've had a nightmare. Perhaps it's time to send them off and be relieved of this stress lol.
Forks gently settling down to almost no travel during test ride, although air pressures seem to remain the same. Rebound adjustment seems ok.
One last bash tomorrow, then off to Lo Co next week if i can't find a fix, who i bought the kit from.
FRUSTRATION UPDATE:
Took the lowers off and way too much oil in the damper lower leg and I measured less than 100ml left in the damper. Inspected the damper unit and the bottom seal head O ring was clipped in several places, presumably during reinstallation i think on the sharp edge the circlip sits. Problem is it too some real force to pull it out and then reinstall the first time which doesn;t sound right.
Probebly boring everyone to death, but RESULT!
Fished the old O ring out of the bin and the damper reinstalled a lot easier than the first time - perhaps fork fluid helps more the grease?
Also covered the O rings in the dual air with plenty of judy butter as suggested by Rock Shox video, and when reinstalling made sure all the air was out as it was `sucking up' when trying to pull out to grease.
So, getting full 140 travel and the damper lock out is now working.
It is good that you got there in the end.