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Brain Fade Rebuild Disassembly 1. Prepare your work area. Lay out clean shop towels to store and organize the shock parts on.
2. Put on your safety glasses and use rubber gloves.
3. Remove mounting hardware before disassembly.
4. Prepare work area—lay out clean shop towel to store and organize parts on.
5. Put on your safety glasses (always protect your eyes); rubber gloves if desired.
6. Clean exterior of shock before starting to disassembly of shock.
7. Un-thread the air cap and deflate all the air out of the air sleeve.
8. Remove the travel indicator O-ring from the shock body.
9. Un-thread the air sleeve from damper (counter clockwise).
10. Clean the inside area of the damper with a shop towel.
11. Remove the plastic ball with a dental pick and remove set screw slowly with 5/32” hex key, to release 200 PSI nitrogen charge.
12. Remove the rubber filler pellet with a dental pick.
13. Un-thread the 2mm set screw on the side of Brain Fade blue knob (you do not need remove the screw completely).
14. Lift the Brain Fade knob off. Remove the two detent balls and spring from reservoir cap. Clean and set aside the balls and springs with knob.
15. Remove the white back up bearings and seal.
Caution! Be very careful; do not scratch the seal gland.
16. Clean and inspect the bottom out O-ring and the two thin washers.
17. Place the body eyelet into a soft jaw vise, and remove the bearing housing by un-threading it counterclockwise with a 22mm open end wrench.
18. Pour the used oil into a drain pan. Clean the body and set it aside.
19. Place the shaft end eyelet into soft jaw vise, and un-thread the damper piston bolt with a ½” socket wrench. Keep the piston and bolt and piston valve assembly together, and set everything aside on a clean shop towel. Inspect the shims, piston, and glide ring. Replace as needed.
20. Remove the bearing housing from the damper shaft.
21. Remove the bottom out washers and urethane (yellow colored) O-ring; clean and set aside.
22. With the reservoir eyelet end of shock clamped in the soft jaw vise, remove the nitrogen reservoir end cap with a 15/16 socket wrench.
23. If the reservoir assembly comes off, remove the nitrogen filler end cap by holding onto the 16mm wrench flats on the opposite end.
24. Set the shaft eyelet aside.
25. As the nitrogen reservoir end cap un-threads from the reservoir body, you will see the Brain fade adjuster rod and Brain Fade adjuster tip with a spring inside the adjuster rod.
26. Gently pull the Brain Fade adjuster rod from the silver adjuster assembly (be gentle, as you will find a very small O-ring inside the silver adjuster.
27. Un-thread the Brain Fade adjuster assembly with an 11mm open end wrench.
28. This photo shows the Brain Fade adjuster assembly taken apart.
29. Clean, grease, or replace the Brain Fade adjuster assembly O-rings as needed.
30. Grease and assemble the Brain Fade adjuster assembly back together.
31. Using a plastic O-ring pick, remove the Brain Fade adjuster rod O-ring. Clean, grease and replace as needed.
32. Grease and install the Brain Fade adjuster tip and the spring back into Brain Fade adjuster rod, and set the assembly aside.
33. Place the reservoir assembly into a shaft clamp, and clamp the assembly into a soft jaw vise.
Caution! Do not over-tighten the shaft clamps, or damage will result to the reservoir body.
34. Un-thread the IV “Brass Mass” assembly from the reservoir body with a 16mm open end wrench.
35. A view of the IFP inside the reservoir body.
36. Remove the IFP by pushing it out of reservoir body with your IFP setting tool, or a self- made tool.
37. Remove the IFP ID/OD O-rings with a plastic O-ring pick.
38. Grease and replace the IFP O-rings as needed.
39. If you suspect problems with the IV assembly “Brass Mass”, it is recommended that you replace the assembly with a new one. Test the IV assembly by pressing the IV “Brass Mass” down and letting it return on it’s own. The Brass Mass should feel smooth!
40. Grease and replace the O-ring and at the base of the IV assembly, and set aside.
41. Replace the O-ring in the threads of the shaft eyelet/reservoir mounting hole, as needed.
In most cases, the rebuilding of the brain fade damper shaft/eyelet is not required, so you can choose to proceed directly to the Assembly section.If you feel the need to work on the damper shaft/eyelet, please follow the damper shaft and eyelet maintenance procedure below. The photos shown are from the DHX Air service section, so the parts in the photos will be a little different than the ones found on the Brain Fade shock.
Damper shaft and eyelet maintenance: 1. You will need to heat up the top of the eyelet to soften the red Loctite; warming it to the touch works best. Do not overheat.

2. Using a 1/2" bar for added leverage, remove the eyelet from the damper shaft.
Caution! Do not allow the damper shaft to spin in the shaft clamps while also taking care not to over-tighten the vise, or damage to the shaft finish may result.
3. Clean the Loctite from the threads on the shaft, the eyelet threads, and the eyelet shaft threads.
Slide the rebound adjuster knob out from the eyelet.
4. Remove the rebound adjuster rod while holding onto the rebound knob (it may fall out as you slide out the rod). Inspect the rebound adjuster rod O-ring, and clean or replace as needed.
Remove the rebound knob. Take note of the knob's orientation; the slots on the knob will point to the DU bushing.
5. Remove and inspect the O-ring located inside the threaded bore of the eyelet. Replace as needed. Set this assembly aside for now.
6. Rebuild the bearing housing with a new shaft seal, and install a new O-ring on ID threads (where the damper body threads into).
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All the major components have now been disassembled.
Clean and inspect and all the metal parts! Inspect, replace, and grease the seals and O-rings, as needed.
Assembly 1. Install one bottom out washer, O-ring, and the second bottom out washer onto the damper shaft.
2. Install the bearing housing onto the damper shaft.
3. Install the damper shaft hydraulic top-out washer onto the damper shaft.
4. Install the piston assembly and the piston bolt onto damper shaft.
5. Torque the piston bolt with a ½” socket wrench to 75 inch lbs.
6. Install the Brass Mass assembly onto the eyelet. Thread it in all the way until it bottoms out in the eyelet.
Note: Final torque will be applied in step 23 when torque is applied to reservoir end cap.
7. Grease the ID threads of reservoir and install the IFP into the end that has the smaller ID bore.
Note: The ID of the reservoir has two sizes of ID bores.
8. Gently push the IFP past the reservoir end cap threads as seen here. The IFP should fit correctly in bore.
9. Using an IFP setting tool mark the height to 1.380”.
10. Set the IFP to the depth of 1.38” and set reservoir aside.
Note: The FOX Racing Shox Production line uses a different method to fill the brain shocks with oil.
We are going to show you how to fill the shock with oil with out using a expansive vacuum filling machine. You will need a deep oil tub and clean oil. We also recommend that your wear rubber gloves during this under oil fill procedure.
11. Major components are ready to submerge into the oil tub.
12. Submerge reservoir eyelet end with brass mass assembly into oil tub.
13. Under the oil move the brass mass back and forth to remove any trapped air in the assembly.
14. Submerge reservoir with the IFP preset to 1.380” into oil tub.
15. Submerge shock body into oil. All major part are now submerge in oil tub.
16. Under oil thread IFP reservoir onto the brass mass assembly until tight by hand.
17. Keeping assembly under the oil push the bearing housing all the way down to the damper piston and then thread the shock body onto bearing housing until hand tight. Let assemblies lay in oil as you move onto the next step. This will allow any remaining air bubble to escape from the parts.
18. Make sure the Brain Fade adjuster rod tip and spring have grease placed on them. This helps to keep them in place for the next step.
19. Carefully left reservoir out of the oil. You want oil to remain in the reservoir above the IFP. Install the Brain Fade adjuster rod with spring loaded tip into oil and down through the middle of the IFP.
20. Now you can pour the excess oil out of the IFP chamber. Note: with adjuster needle through the IFP no oil or air will get into the damper unit.
21. You can test the Brain Fade adjuster by pushing on it with your finger tip, you will feel the rod move slightly in and out as you apply and release your finger pressure.
22. Install reservoir Brain Fade reservoir end cap. Make sure you center the Brain Fade adjuster rod so that it will correctly set into the O-ring that is in the Brain Fade reservoir end cap.
23. Torque the reservoir Brain Fade reservoir end cap to 110 inch lbs. with a 15/16 socket wrench. This will also apply the proper torque to the bottom nut that secures the assembly to the eyelet.
24. Torque bearing housing with 22mm crows foot to 20 ft. lbs.
25. Grease the detent spring and ball for the Brain Fade blue adjuster knob.
26. Install springs and balls into detent holes (2) in the reservoir end cap.
27. Lightly grease the bottom side (detent pockets) of the Brain Fade blue adjuster knob.
28. Install Brain Fade blue adjuster knob onto the hex adjuster being careful not to displace the small balls from the detent pockets.
29. Using a 2mm hex key thread in the set screw until tight. The torque required 14 inch lbs.
30. Test function of knob by turning back and forth, It should have smooth action. Install the rubber filler pellet and set screw.
31. Charge shock with 200 PSI of Nitrogen.
32. Torque pellet retainer (set screw) to 110 inch lbs. After filling and press fit the white plastic ball.
33. Test Brain Fade shock on your hand dyno. Test the shock in the soft and in firm modes. You should be able to tell the difference and the shock should feel smooth and pure free of air bubbles.
34. Grease and install bearing housing back up rings and air chamber main seal.
35. Grease and install bearings,seal and dustwiper into the air sleeve as needed.
36. Install air sleeve.
37. Install Travel indicator O-ring.
38. Pump up the air sleeve to your customers requirements or set to the stock pressure setting of 150 PSI.
39. Install air cap.
40. Clean the shock, install new decals if required.
Note: Shock mounting bearings and long arm extension are Specialized bicycle company parts! FOX Racing Shox does not stock these items.