I believe it is likely the tie rod ball studs are worn since you had the same problem before upgrading to PS. It's been my experience that the original type do not work well with power steering. The improved tie rod with the newer type tie rod ends are available from a number of aftermarket sources such as Brothers, Truck Shop, CPP, and others. Also the 400 series (Toyota) steering box operates with about 900 psi while the standard GM pump delivers about 1300 psi. If the pump pressure is too high it has the potential to cause the problems you are experiencing. Kits to reduce the pressure are also available through aftermarket sources.
Fred
Last edited by rfs56trk; 02/10/2018 5:37 PM.
