If you are asking for long term use of DOT 4 fluid and if it had any ill effests I'm an example.
I change brake fluid annually. I have used DOT 4 fluid since the first change when the car was one year old. I have had no hydrauilic brake or clutch system issues. The car was purchased in August of 97 and has just gone over 200,000 miles. Most of the time that has been with Valvoline Synpower brake fluid.
So it seems to be working fine on my 98 SVT E0.
