'91 DeVille, great shape - From time to time when I apply the brakes the resistance on the pedal is peculiarly high. Then, while maintaining the pressure on the pedal resistance and the pedal fade back to normal. There is also a slight sensation of pulsing from the pedal. This is accompanied by a sound similar to the sound made when applying the brakes when the rotors are wet, like after going thru a car wash. Occasionally while driving, usually below 20 mph I'll hear a sound as if a pump is running...the pedal pressure is always high when I hear this noise. The car always did this the 3 years I've owned it but it seems to be happening more regularly now. I suspect it's something to do with the ABS system. Anyone have any clue what's happening, how it can be fixed and am I heading for catastrophic failure one day?

 

I am not a Cadillac expert but this sounds exactly like the ABS is activating. The ABS blocks off the brake line pressure coming from your foot on the pedal and pressurizes the brakes itself. This gives you the hard pedal feel. It sounds like a pump operating when ABS is on too. I would think this could be a hazardous situation if it applies the brakes when you don't expect or harder than you expect. It could be as simple as a bad wheel sensor. I would get it fixed.

chuck
98 Deville Concours