One problem related to power steering fluid has been reported for the 1998 Ford Mustang. The most recently reported issues are listed below.
There has been a significant loss in steering stability. Everything from the power steering pump to the rack and pinion show no signs of leaking. I've had the ps lines replaced as well as the ps pump, because if the lack of stability and the problem still persists. Ps fluid has been replaced and bled. And the pump is still very loud (it was always loud, the new pump is the same way. But that's more annoying than a safely concern). I'll be driving down the street and on the highway and the car will suddenly veer to the left or right. Car has new tires and has been aligned recently.