Well, I replaced my booster with the rebuilt unit that I bought from Autozone and started the car up and no change. I still hear hissing and have a rock hard pedal. I think I got a bad booster from Autozone. When I press on the brakes the car's idle gets rough and when I unplug the booster it sounds great. I think I'll go to Napa even though it is more expensive. Chad 1973 Imp 1966 Galaxie __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/