After my recent bout of stupidity in which I had to replace both shocks, I have noticed what an amazinglysmooth ride I have since I got everything back together. I am sure part of the reason is new parts but I don't think that explains everything. The replacement air shock I got was minus an unknown amount of fluid so I ended up draining the rest and refilling it. Now I started thinking about it. It has fluid just like the forks, rear end, brakes and clutch. I know that a lot of folks change those fluids on a regular basis. Well the air shock has fluid that is regularly exposed to outside air when adjusting so it stands to reason that it should also get contaminated after a while and lose it's damping ability. I know that there is dessicant in the compressor that should filter out contaminants but even still, I imagine that it will still go bad after a while. Why shouldn't this be changed on a regular basis too?
I discovered that it really isn't that hard to do. It does need to be removed from the bike to do it as it needs to be turned upside down to drain it. Right saddlebag needs to come off. The air fitting needs to be removed using a 14mm socket and then the top and bottom shock bolt need to be removed. After that, turn it upside down and pump it a few times but be careful because it will spray out. After pumping a few times, it should be pretty much drained. Next turn it right side up and slip something through the bottom mounting hole so you can stand on it and keep it up right. I used a long screwdriver. At this point I found one of the cone shaped fittings from my mityvac kit that was cone shaped on one side and flat on the other. I believe I used the second one from
the top on the right. The backside fit inside the opening for the air fitting pretty well by winding it in. I then attached a length of clear hose to it. Next I used a syringe that had a cone shape on the end that fit tightly into the other end of the clear hose. It was similar to this one and can be found at pet supply places for a couple bucks: http://www.birdb.com/osc/product_inf...mp;language=en
I bought a bottle of Honda SS-7 suspension fluid. I pulled the plunger of the syringe out and filled it to 60cc=60ml of fluid holding my finger over the end, stuck the plunger back in and turned the syringe upside down. Leaving the shock collapsed, I then put the syringe into the other end of the clear plastic tube. While holding the syringe in one hand, I pulled up on the shock while standing the screwdriver. This created a vacuum and while squeezing the syringe, the fluid got sucked right into the shock. After the fluid went in, I pulled the plunger out to release the vacuum then pulled the syring off to fill it again. I collapsed the shock again and repeated the above step a second time. I did this one more (third time) but only filled with 20cc=20ml of fluid. The capacity of the shock is 140cc=140ml of fluid. This last time, I didn't collapse the shock. I did however pull the plunger out on the syringe and put the plunger back in squeezing one last time to force all the fluid out of the hose. I then brought the shock back over to the bike and installed the top and bottom bolts. FYI, they only need to be torqued to 17 ft lbs so this is just slightly more than snug. I then attached the air fitting making sure that there was still the o-rings on either side of the banjo fitting.The air fitting only needs 4 ft lbs so basically just snug.
This procedure was no more difficult than changing out the fork oil or anything else, I may just to add it to things to periodically change.