Hi, I just recently purchased a '93 Blazer S10 4.3 Vortec Engine,4 Door, 4WD. The brakes worked fine for a few hours of driving, then i got home and went to pull into the driveway and the brakes are very hard to push down and don't stop very quickly. I have read that you are supposed to pump the brake pedal then hold it down and start it and see if the pedal moves to the floor. It moves to the floor. I'm not sure if it the booster or master cylinder or what. I am hoping someone can tell me whats wrong and how to fix it. Thanks.