82 XJ750J Maxim fork cap bolts stuck

I am currently in the process of replacing my fork seals, but I have run into a substantial roadblock. I cannot, for the life of me, remove the threaded aluminum cap bolts on top of the forks. One of them is so chewed up from my efforts (and what I believe are the previous owner's efforts) I don't think it will hold up to much more abuse.

Are there any tricks to this I am missing? Do I need to somehow remove the center air valve/control rod? I removed the retaining clip before trying to remove the cap bolt, and noticed that I was able to shift the valve up and down a few millimetres, as well as freely rotate it in both directions, but it did not move any further.

I was luckily able to remove the damper rod bolt on one fork with the top cap bolt still on (no holding tool needed), and thus was able to replace the seals on it. Unfortunately, the other fork is proving to be less gracious, which is why I have concluded I must fully disassemble the fork.

Any help is appreciated.

 

HEAT the top of the outer tube with a torch (or a hi-wattage heat gun). Using freezing spray or ice cubes in the cap bolt. Penetrating oil. Prayers.

 

and file some flats on the cap so you get a better grip on it.
You'll want to replace it anyway

 

Looks like you have it removed, but just in case...if you are putting it in the triple clamps to get a grip on the tube, only tighten the lower pinch bolts. If you tighten the uppers, you are basically tightening the threads around the cap and it's near impossible to get them off. (lesson learned early in life for me)

Also use a 6-point socket instead of a 12 if you have one so it's less likely to do damage.

 

I went out and bought a socket that fit on the head, but it was too far gone and I ended up completely rounding it out. Then, using a healthy dose of heat, ATF/acetone, and vice grips, I managed to get it off. I was lucky to find a replacement cap bolt at my local motorcycle shop, so my forks are now complete.