Dan-

Unfortunately, it is my understanding that the hydraulic/modulator unit is not repairable. That is, the unit is factory sealed and no repair parts are even available. You may want to try gently tightening the connections, but this probably won't solve a leak problem. The pressure reducing valve is the small cast unit that connects directly to the MC. If your leak is here, you may have more success, and the part is much cheaper anyway.

I speak from some personal experience after discovering a hydraulic unit leak on a 1995. You will discover that this part is very expensive ($1400). I refused to pay this, and ended up buying a salvaged part for <$100. So far, it's working fine. Good luck.

Gerald C