Stop ABC fluid cap leakage- buy new seals (cl55,65)
I got tired of my ABC and P/S reservoir caps leaking/weeping ABC fluid all the time, so I got around to finding replacement seals for the caps.... Part 210 327 00 60, you'll order two since they are the same on the ABC and PS reservoir. While you're in there be sure to wipe the rim of the reservoir clean. Expensive o-rings at ~$5.00 each, but who cares, it's probably a once-in-a-decade replacement. It's only been a week since I've replaced mine, but there has been absolutely no more weeping of fluid. Be extremely careful not to get anything in the reservoirs. You can pull the o-rings off over the filters without removing them.
Additionally, you can replace the cap of your PS reservoir dipstick (I could not find a replacement for the PS reservoir) with the rubber cap off a new ABC reservoir dipstick (they pull off with moderate force, no glue). Mine had split at the seams and weeped a small amount.
Now you know!