I am clueless now!!!! I really thought that the proportioning valve was the problem,but apparently not. My balzer pulls to the right big time, and I have replaced everytninhg brake related except the booster. I just took my blazer for a test drive after replacing the prop. valve and master cylinder and the first 5 stops were pretty straight, but after that it was back to pulling to the right. I bench bled the master cylinder, so that is not a factor. Besides other suggestions to check I was wondering about the rubber button on the valve. I went to push it and it wasn't sticking out like I remember the original had. I'm looking at the old one right now and it doesn't stick out anymore either now that it's off the blazer. Is this just because it's not hooked up or does it only come out when the brake pedal is pressed? Please if you guys have any other suggestions besides the prop. vlave then let me know. When I had the balljoints replaced the shop said my bearings looked great. Could it be the spindle or rotor or hubs. I'm basically second-guessing everything that I replaced now, becasue I have replaced everything and still no luck.