The high pressure power steering hose will commonly leak fluid; it should be replaced.
Car Problem Reports
Buick Park Avenue High Pressure Power Steering Hose Can Leak Fluid
Buick Park Avenue Problem
Visitor, 1999 Buick Park Avenue, 177,000 mi
Power steering fluid leaking. Mechanic checked and the PS gear was leaking at the gaskets as well as the PS hose. Had to replace both. Cost was $1100.00 parts and labor (6 hrs @ 90 per hr). Gear was 470 and hose was 70.