Cannot get it to bleed

[JoeMaico]

Well, I attempted my first shock service and it has not gone to plan. I replaced the shock piston with a new one because I did not want to have to deal with cutting the Teflon band, and I replaced the large o-rings on the reservoir cap and piston that come with the gasket kit. I removed the clevis and tried to service the shock seal, but I could not get that little cap that requires a 2.5 mm pin wrench to unscrew, to get at it. So, I just greased it up and reused it. I put it all back together (keeping the shim stacks in order), and I cannot bleed the shock. In fact, it takes all of my weight to just get the shock piston to go down a small amount while holding pressure on the reservoir piston to keep constant back pressure. And you can forget about cycling the piston up and down to remove any trapped air. To remove the piston, I have to grab it with both hands and pull with all my might to break the vacuum to get it out. I never serviced it before, but I have to assume that oil is supposed to flow through some bypass ports when stroking the piston by hand, and is forced through the shims when operating at higher cycles. The service manual shows the tech cycling the piston with one hand while pushing down the reservoir piston with the other. In no way can that be accomplished with my current situation. So, obviously I have screwed something up.

I am thinking that the little needle inside the shaft is frozen shut. When I blow through the end of the shaft (piston side) it seems plugged. There are the four holes on the shaft below the piston that I have to assume is part of the bypass. I have run suspension clean and compressed air through this assembly. The fluid from the spray does come out the holes, but not with any force – more like a liquid dribble. My thought is that oil should flow freely through the holes and out the top on rebound stroke and through the top and out the four holes on a compression stroke. If oil is flowing through these holes, and around the piston, then I am hoping that allows you to cycle the piston by hand during the bleeding process. The gasket kit comes with replacement o-rings for the needle, but I cannot see how to get that needle assembly out of the shaft. And, the shop manual contains no instructions on how to accomplish this task either.

So, if anyone has experienced a similar issue, I would appreciate knowing how you resolved it. If that pin assembly has no bearing on the oil bypass, then I am completely lost on why the piston will not cycle by hand. And if oil is supposed to flow around that pin (in both directions) has anyone ever serviced it and how did you accomplish removing the tube (that appears to be press fit) that holds the pin in?

I have sent some mails to suspension shops in the next city (there are none in mine), to see if they want to service the shock in its current state (no replies yet). I don’t want to buy a replacement shaft just yet (includes the needle assembly). But that will probably be my next step, if no shop wants to deal with it.

[mike307]

hey joe , so my procedure wich work like a charm ..
1. low speed comp adjuster full in and then like 2-3 click back ,
2 , put oil in the reservior flush ,
3 put piston back in the reservior and push all the way down , a litle oil will get out after you put the piston back
4. put oil in the body near full like 3cm off top ,
5 i like to leave the shock like 5 mins to all bubbles to come out ,
6 REB CLICKERS set to stock clicks , then with a rod push the reb needle back manualy from the top hole !!! without presure the needle will not
move ,when the shock is presurized then the presure is forcing the needle to move..
7 piston with rod in the body and bleed it, push the rod in first slowly then back slowly , add oil ,, then few times push in fast and slow out , if you
pull out fast then you make vacum and you get air ..
8 after the movement is plush , all the air out put oil till near flush,
9 you need to push and hold the reservior piston all the way in, put the seal head in slowly , on the seal head is a small bleed hole from the side,
when the oring on the sealhead starts to seal with body THEN let go the reservior piston ..
10 clips in both sides, presurize to 150psi or 10bar .. DONE ..
Iff you got question fell free to ask .. BTW i am using normal air like last 2-3 years without a problem .. if you are racing then go for nitrogen ...

[JoeMaico]

Mike, THANK YOU! You supplied the critical piece of information I was missing. The fact that you have to manually reset the bleed valve to the open position. That key step was missing from the service manual (that and how to replace the bleed valve o-rings). I used a long allen wrench) and pushed down on that needle, and it opened right up. I could then blow freely through the top of the shaft. With your info I was able to get it bled and put back together. I only have a hand pump, but I did pump it up as much as I could and tested it out (by hand). It seems to compress and rebound without hesitation. I will go to a shop and get a nitrogen fill - that is more accurate to 150 PSI. I also used your trick of maximizing the back-pressure by cranking in the low speed compression. I am sure that helped the bleed process as well.

Thanks again

joe

[mike307]

Hey joe , no problem .. i am glad that it worked out .. last year my shock was apart like 30 times for valving changes . But now i got figured out..And the most critical think is using a good quality oil ...

[JoeMaico]

For future reference, did you ever figure out how to remove the bypass needle to replace the o-rings that are included in the gasket kit? I am thinking that threading a small machine screw into the shaft that holds the needle in, then with the appropriate tool, pull on the screw to extract the press fit shaft. I wont be worrying about it now, but on the next rebuild, it will be something that I will want to look into.

joe

[mike307]

i got that kit too , i tell you the truh , my shock got around 400 hours with second body and those orings are stock , i never changed them , but i got friend who is good tuner , i can ask whats his procedure to remove the needle ..