Shock oil


Well-Known Member
Can anyone give me some tips on changing out my shock oil? I just need to know what to do after I have the piston out and have drained the old oil. I've heard you have to slightly pressurize the shock body, but I don't know any details. BTW this is for a pair of King 2.5' prerunner series w/res (no bypass tubes). Thanks in advance.


Well-Known Member
I was going to type it all out, but you can look up the post "shock rebuild video with Brett King" (or something) and get better advice. You can't hear his voice very good, but once you see him do it, it'll be a piece of cake.



Well-Known Member
I'll have to check that out, but in the meantime, where in north county can I buy shock oil? Would motorcycle fork oil be sufficient or not?


Well-Known Member
the video can be found on

Here is a copy paste from an email reply I got from fox shox asking how to rebuild their shocks:

1. Clean shock. Loosen set-screw located on bearing cap.
2. Loosen bearing cap with a spanner wrench/pliers. Remove bearing cap assembly.
3. De-pressurize shock completely.
4. Push bearing assembly down to expose snap ring. Remove snap ring.
5. Remove shaft / bearing assembly, by rocking back and forth and pulling out at the same time.
6. Depress reservoir end cap. (Schrader end). Remove snap ring and reservoir end cap.
7. Dump oil. Depress reservoir end cap. (Hose end). Remove snap ring, remove hose and end cap from reservoir. Remove IFP (Internal Floating Piston).

8. Clamp shaft assembly in a vise, using the eyelet. Remove valving, bearing assembly, and bearing cap assembly. Make sure to keep all valve plates and piston in the same order as removed.

9. With a scribe remove all seals from bearing cap, bearing assembly, reservoir end caps, and IFP. Clean all parts.
(Be careful not to damage any sealing surfaces)
10. Inspect all valve plates and damping piston, look for cracks or any signs of fatigue.
11. Check shaft to see that it is not bent or has any deep pits. Replace if required.
12. Install new seals on all parts. Use a small amount of grease on bearing assembly and cap.
13. Install bearing and cap assemblies onto shaft. Be careful not to damage any seals, we recommend using a FOX bullet tool (398-00-094-A) for 5/8 or (398-00-095-A) for 7/8.

14. Install valving assembly and lock-nut. Torque nut to 30 ft./lb.
15. Clean body assembly, place in a vise open end up.
16. Clean reservoir body. Lube re-sealed IFP, install flush with the end of the reservoir body. (Schrader valve end)
17. Fill reservoir with oil. (FOX 5wt). Reconnect reservoir assembly to hose assembly. Install snap-ring, check to be sure it is seated completely.

18. On the 11" long reservoir, push the IFP in 8" from the open end of the reservoir. On the 8" long reservoir, push the IFP in 6" from the open end of the reservoir. This will force any en-trapped air into the shock body.

19. Fill the body with oil, leaving a 2" air gap at the top.
20. Insert shaft and valving assembly into shock. Gently move the shaft assembly in and out until all the air bubbles are removed. You are trying to bleed any air that may be trapped in the shock.

21. Check the IFP location, it may have moved. Reset if needed.
22. Top off the shock with oil to about 1/4" from the top.
23. Slowly insert the bearing assembly into the shock body. Oil will come out the bleed hole built into the bearing. Push the bearing in so that the snap ring can be installed.

24. Install the snap ring. Check to be sure it is completely in its groove. This is very important!
25. Install bearing cap assembly. Screw it onto the bearing assembly until it is snug.
26. Lube and install the reservoir end cap. Install the last snap ring.
27. Compress the shaft all of the way into the shock. This should set the reservoir end cap into position. (It should make a pop / snap sound).

28. Pressurize the reservoir with 180-200 psi. Install reservoir valve cap.
29. Tighten down bearing cap assembly. Tighten bearing cap set-screw.
30. Remove the shock from the vise. Compress the shock to make sure it is working properly.

You can get your parts from the dealers below.

Kartek (909) 628-2525 /
Mckenzies (714) 441-1212 /
Off Road Warehouse (858) 565-6095 /
Race Ready Products (619) 691-9171