Car Suddenly Hard to Turn Left on 1998 Buick Riviera

I had just purchased the car used, and was driving it back home. I was making a U-Turn and about half-way thru the turn the power steering just quit. Now the vehicle has power steering to the right, but not to the left. Any suggestions would be appreciated.

Asked by for the 1998 Buick Riviera
bad o-ring seal on slave cylinder left hand side, 50 cent part
2 answers
The fault is most likely with the power steering rack. However, please have the problem diagnosed by a qualified technician before replacing any parts.