1998 Expedition Strange Brake Problem

I have a 1998 Expedition that has been very well maintained. Currently we have 170k miles with minimal problems. The most significant being the a couple of the coils going bad and being replaced. However, just recently I have noticed a couple of things. First, I noticed the ABS light coming on typically when I was making a left turn at over 10 miles an hour and just touching the brakes. However, this does not happen every time. We initially thought it might just be the cold weather and the sensor freezing. But...then in the last day or so another strange problem occurred, when making a slow left turn (such as when turning into a parking space), the pedal stiffens, vibrates (much like when the ABS is activated) and very little brake pressure is applied until I press very hard on the brake pedal. Otherwise the brakes perform flawlessly. The brakes were replaced about six months ago by a local vendor. Any thoughts?

You may have a sensor rhat does not have the proper air gap or one sensor is starting to fail. It is hard to tell which one it is without putting a scanner on the vehicle and driving it while monitoring all sensors.

Way2old you obviously are not2old to know your stuff. The left front ABS sensor was bad and has been replaced. Problem fixed. Thanks for your help.

Appreciate the kind words. Thanks for posting the fix also.

I have the same problem with my 99 Expedition. Can you advise how you diagnosed the problem, what was the fix and how much did it cost?