Two things. First, chances are you are loosing vacuum to the brake booster. Check the hose. If it is good, have the booster vacuum tested.
Next, it the ABS light has come on, have the computer scanned for trouble codes that will help identify where the problem is coming from. Most parts stores will do it for free.
Let me know what you find or if you have other questions.
Wednesday, March 10th, 2010 AT 8:45 AM