Ok a day or two ago i got in my car (98 GTP) and the brakes seemed VERY numb and it was hard to stop the car. So i checked the brake fluid and the thing was almost dry. I filled it up and yesterday i popped the wheels off and found that the proportioning valve is leaking. And, to top it off it looks like the previous owner just tried to seal it up with silicone...really people lol...so im gunna order the part but my question is once i replace the valve with a new one do i have to bleed all four sides or do i need to just bleed the side of with the valve i replaced? or the third option should i bleed all four just to be safe? Also, i herd from one guy that our cars have a "self bleeding system" is this true???