Degraded Rubber on Corny Kegs

[PVH]

I looked around for an answer to this. Please direct me to a thread that covers my question if I missed it.

I have a very used cornelius keg whose rubber on top and bottom has undergone a chemical change of some sort. It is rough, dry, and gives up a serious black smudge.

Anyone know how to remedy this? I scrubbed a small part, let it dry, and hit it with 303. That seemed to help. Any ideas?

 

[DeafSmith]

I had the same problem on one of mine. Armor-All fixed it up. I also saw in another thread someone recommended a product called Mother's Back to Black, which I think is available at auto parts stores. The Armor-All worked fine for me.