1989 Toronado Trofeo - HELP
 

I have a 1989 Oldsmobile Toronado (Trofeo) with ABS, I am trying to figure out the problem with my brakes, my Master Cylinder has been replaced before and many parts having to do with the brakes have been replaced from what my mechanic has told me. My mechanic is not familiar with my car model so he was unable to diagnose the problem. I believe the brakes have been bled correctly. What happens is when I press on the brakes, the pedal will easily push to the floor, and the ABS will kick in, causing the brakes to grind (not actually grind, but thats how it seems) If I push on the brakes very hard and fast, I have no chance of stopping as it will lock up. Another thing that my mechanic has told me is to test the Accumulation Pressure + system for codes. Please post any ideas as to what my problem might be.