So I am hoping someone can help me. I pulled the center shock apart for starters to do an inspection and oil change. I have access to nitrogen but can anyone post a picture of the tool to hook nitrogen into the shock? I am thinking I will design a tool with the 4mm x.7 to thread into where the screw is and charge. I would love to see a picture of the proper tool though.
Second, I haven;t worlked with an IFP shock before. There is a dimension for this but how do I apply that? I can move the floating piston wherever I want but is that ok?
What is the proper assembly procedure? I figured I would fill/bleed with oil and then charge the gas side with the 285psi.
These are simple shocks, someone has to be able to help me who does it themselves. Thanks in advance and no I don't want to send them out since I do my motocross suspension all the time and it is far more advanced.
Second, I haven;t worlked with an IFP shock before. There is a dimension for this but how do I apply that? I can move the floating piston wherever I want but is that ok?
What is the proper assembly procedure? I figured I would fill/bleed with oil and then charge the gas side with the 285psi.
These are simple shocks, someone has to be able to help me who does it themselves. Thanks in advance and no I don't want to send them out since I do my motocross suspension all the time and it is far more advanced.
Hi Perf in the US has/had some shock servicing tools because I looked into trying to get the gear to do just what your doing but I couldn't find any literature to help get me started.
Seriously no one does this? Wow.....it will make such a difference. Doing an oil change is not that hard at all.
If all goes well, I may create a video of how to change the oil in the shock the next tiem I do it and post a link.
If all goes well, I may create a video of how to change the oil in the shock the next tiem I do it and post a link.
chris189 said:
I pay a guy $50 bucks to do it. He builds prototype shocks for Norco so he knows what he's doing. Do you?
vipertriplexxx
New member
You need to buy a fill needle, seal kit and oil for rebuild. To fill the shock with nitrogen you take out the silver screw on the brass nut at the base of the shock and stick the needle into the rubber under the screw. I fill to 250lbs. for rear shocks, and 200lbs. for front shocks. More pressure will stiffen the shock, but not enough pressure will cause the shock to loose it's dampening abillities in big bumps. Here is a link to deycore, they have all you need to do shock rebuilds. I use 10wt. amsoil, but 7wt. oil will be better if you want to soften up you ride.
http://www.deycore.com/tools.htm
As for floating piston depths, Yamaha isn't giving up the ghost. I set the FP depth so it is 1/2" deeper than the nut on the end of the shock shaft. thats the nut that holds the valve stack on the end of the shaft. Remember that the depth of the piston will have to include how deep the seal pack sits in the body of the shock. This will give you minimum clearance to prevent the nut from hitting the internal piston. Setting the piston deeper will increase stiffness of the shock as it is depressed. If you set to deep, the piston will bottom out inside the shock. When you put the shock back together you fill it with oil and insert the shaft assembly into the shock, pulling it up and down slowly getting bubbles out. Before you push the shaft seal into the shock make sure the shock rod is completly depressed into the seal as if the shock were bottomed out. Oil should overflow out of the shock as you put the seal pack into the body of the shock. Charge shock , your done.
http://www.deycore.com/tools.htm
As for floating piston depths, Yamaha isn't giving up the ghost. I set the FP depth so it is 1/2" deeper than the nut on the end of the shock shaft. thats the nut that holds the valve stack on the end of the shaft. Remember that the depth of the piston will have to include how deep the seal pack sits in the body of the shock. This will give you minimum clearance to prevent the nut from hitting the internal piston. Setting the piston deeper will increase stiffness of the shock as it is depressed. If you set to deep, the piston will bottom out inside the shock. When you put the shock back together you fill it with oil and insert the shaft assembly into the shock, pulling it up and down slowly getting bubbles out. Before you push the shaft seal into the shock make sure the shock rod is completly depressed into the seal as if the shock were bottomed out. Oil should overflow out of the shock as you put the seal pack into the body of the shock. Charge shock , your done.
found the spec on your piston height,115mm from edge of cylynder to edge of piston.Not the inner (deeper) part of the piston.
thanks guys. Yes srx 700....it's not that complicated. Motocross stuff is a lot more important and far more complicated than these cheap shocks on sleds. I have been doing it for a while. Not revalves, just service.
Thanks Viper....One question...why do you use such heavy oil? I was going to use 3wt just like in moto...especially when the temps are so cold. I use 5wt in my forks too....10 wt just sounds heavy. Did you find out what they use from the factory?
Thanks Viper....One question...why do you use such heavy oil? I was going to use 3wt just like in moto...especially when the temps are so cold. I use 5wt in my forks too....10 wt just sounds heavy. Did you find out what they use from the factory?
vipertriplexxx
New member
I have found the synthetic oils like maxima and amsoil don't change much in vicscosity with temperature like the factory dino oils. I did a SUS cup check at about 20 degrees and found amsoil 10wt. was very close. maxima 7wt. emptied sooner. I have tried 3wt. in some front shocks, and they were like wet noodles. All depends on how they are valved.
Ok, so for stock kyb shocks you have found that 10wt is very close to stock? I am leavign the valving alone for now.
Viper, so as far as filling.....is there currently a small hole through the rubber already? If not, do I make one with the needle and it will somehow seal afterward? Thanks for your help.
vipertriplexxx
New member
Yes,Yes, It will re-seal when you pull out the needle, just stab it in.
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