99 F150 4WD 5.4 ABS. ABS came on yesterday, brakes worked fine though. Stopped for gas and started to pull out and pressed brake pedal to stop for traffic. Pedal never moved (like stepping on a rock), zero braking action. Pressed harder, felt two kinda pops in the pedal as it finally moved and the brakes now worked fine again (light still on though).

What in the ABS could cause this? Any guesses?

 

Turned out it was the right front wheel bearing. Guess the bearing going bad was messing up the signal from the sensor. Never would have believed it!!

 

Thanks for letting us know what the cause was. When my LF bearing hub went bad, the RF wasn't far behind.

 

That pop was probably your wheel bearing getting realigned. I bet the wheel bearing was that bad. I've seen folks ignore their wheel bearings and off come their wheel.

 

if you have loud off road tires, you may not hear the bad bearing until it has completely failed.