4000 Series dampers do not require checking nitrogen pressure, but in the event they need to be checked you can do so by using the needle fill tool.
1. There are several tools available on the market. The simplest method is using the AST needle fill tool with a dial pressure gauge. Make sure the maximum pressurefor the gauge is greater than 300 psi.
2. Remove the sticker on the base of the shock (ifrequired). |
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| 3. Insert the fill tool (with gauge installed) in thebase of the strut. Most shocks will have the fill plug on the base of the shock or side. |
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4. Pressure gauge should read:
- 175 psi for all 22mm shocks/struts
- 265 psi for all 14mm shocks or inverted struts
5. Inserting the fill tool will remove some pressure from the shock. You will need to refill the shock once you have removed the fill tool.
6. If possible, you should remove and replace the fill plug diaphragm.
7. Deflate the shock completely.
8. Using a 4mm allen wrench, unscrew the silvernut where the fill plug is inserted. |
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| 9. Pull the black or white fill plug diaphragm outof the shock and replace it with a new one. |
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| 10. Reinstall the diaphragm using a small screw driver. |
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11. Reinstall the silver nut.
12. Refill the shock.
13. Always push the shaft of the shock down into the body until the shoulder of the shaft is nearthe end of the shock cylinder. This ensures the floating piston is working properly andverifies that the nitrogen is being filled sincethe shaft will extend out as the nitrogenchamber is filled. |
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