Two problems related to hydraulic power assist steering system have been reported for the 1998 Ford Expedition. The most recently reported issues are listed below.
Wipers/washer don't always work. Will work if turn signal is turned on.
When driving along a curve at times steering control is briefly interrupted causing a sense of loss of control of the vehicle. I took it to the dealer and explained the problem, they indicated that my vehicle was out of alignment and that my tires needed rebalancing and rotation. I paid for the alignment and they through in the rebalancing and rotation, but the problem persists.