It's very common. You're going to need to replace it. I drove with mine
like that for over a year, carefully checking the fluid level, but I
can tell you it doesn't get any better.

I got a quote for about $825 from my mechanic, and kept putting it off.

I finally bought a rebuilt rack from Jeff at busdepot.com and found the
most excellent instructions in the list archives. Did it myself in two
easy sessions on a weekend, total maybe four hours, maybe six over two
days, I can't remember.

You'll know you have the right instructions if it starts out telling
you to put a glob of dentine gum over the hole in the fluid container.

Be sure to have a 22mm open end wrench on hand, you'll need it three
places.

The only thing I can add to the directions is to take a set of
draftsman's dividers (or something similar, I used a sliding dial
indicator) to accurately measure and record the distance between the
center of your old ball joints and the last thread on the steering arm
so you won't have to pay for a re-alignment if you keep track of left
and right rods. Also, don't toss your old boots until you retrieve the
rubber disk from it, the new boots don't come with them unless you ask.
This disk has a hole in it and fits over the steering arm.

Jim