The high pressure power steering hose will commonly leak fluid; it should be replaced.Google+
Car Problem Reports
Buick Century High Pressure Power Steering Hose Can Leak Fluid
Buick Century Problem
Average Mileage: 133,000 mi (89,000 mi - 160,000 mi)
Visitor, 2002 Buick Century, 150,000 mi
Thing burst while i was driving down the road. Really sucked.
Visitor, 1996 Buick Century, 160,000 mi
steering quit and after filling reservoir, I found all the fluid on the floorboard.
Visitor, 2001 Buick Century
Dealing with this issue now.
Visitor, 1990 Buick Century
replaced hose unit