As I got free time it came up to service my Rock shox revelation air uturn 2010, it was leaking oil from the main seals.
Tools needed:
Beer
24 and 10mm socket
Allen keys
Snap ring pliers
Fork oil 5W, 15W and grease recommend judy butter or slick honey
Spare parts ( seals, beer, o rings )
The process is pretty straight forward, for the first step remove the air from chambers, unscrew the top caps, on the right side remove motion control and take out the oil, next remove left air u-turn cap( there is little snap ring on top ) in left leg there should be little amount of oil, after removing all oil you can unscrew bolts and nut on the down side of the fork, dont unscrew it all the way because you have to use hammer ( recommended a rubber one ) and do a little tap on the cartridges to unbound them from legs, as they can frilly move you can unscrew nuts all the way.
after that lower legs should be free to remove.
After that you can remove old seals and put in the new one, before putting the new one its recommended to leave foam ring in oil for a couple of minutes for better lubrication, if you have enduro seals they will probably came without foam ring , they usually have rubber ones with them this step isn't needed.
Some of the guys usually remove foam rings and instead of them put a lot of grease in their place which is great also but you have to do it more often then.
After cleaning the legs and putting foam ring inside on the main seal is recommended not to apply grease on the contact areas ( seal and lower leg ) because of the pressure in the legs and if there is lubricant you can easily blown a seal while riding, some guys even put some king of glue but I wouldn't recommend that because it would be pretty hard to remove seals on the next service.
After lower legs are done we can go on the upper parts, you can check and clean motion control and rebound cartridges to see if there is any damage.
Then we came to the part of air u-turn cartridge which is on my opinion one of the worst cartridges, there is a lot of problems with it and Im probably doing swap for dual or solo air soon.
For opening it you will have to use snap ring pliers, after cleaning everything and reassembly of the cartridge be sure to put a little amount of grease or fork oil on the o rings.
Then is part of cleaning the stations and inspecting them if there is and damage visible and part is pretty rough I recommend to sand it with high grade sanding paper ( 2000 or 3000 grit ) or even filling it with clear nail polish then sending it to ring it to the level.
Then assembly comes its recommended to put grease on the fork seals, first we put rebound cartridge in the right leg and secure it with snap ring and then put the lower legs, after that you put left side in and secure it with snap ring.
Next you can screw rebound side, put oil in it and screw motion control and check if compression and rebound works, this is recommended to check before screwing left side top-cap and go through all of its travel.
Tip: if the adjustments dont work there is possibility that there is too little of oil and if you cant get whole travel of fork there is too much of oil. I usually put amount of oil to leave about 5-10mm of travel when its completely compressed for some kind of bottom out safety.
After the final adjustment its recommended to put a little amount of oil in the left side for stanchion lubrication then you can screw left side, check fork if its working on all of its travel and then put air in, amount can vary depends on the riders weight and type of ride.
Before putting fork back on the bike clean it from the outside to remove any spilled oil or grease.
Thats it, have a cold one and enjoy your ride. :)