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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29534
Experience:  GM Grand Master Technician 2007. 14 years experience.
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1999 Blazer: my fine until you hit about 4 mph..brake pedal

Resolved Question:

My ABS brakes on my 1999 Blazer work fine until you hit about 4 mph then the brake pedal seems to drop.
Submitted: 5 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 5 years ago.
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
When you press the pedal at a stop, does it sink?
Customer: replied 5 years ago.
The ABS seem to work fine until you slow down to about 4 mph then the brake pedal seems to drop before it catches again.
Expert:  GM Tech (Cam) replied 5 years ago.
Ok, does it do this on dry surfaces?
Customer: replied 5 years ago.
Yes it has been doing this since I bought it 2 years ago. I have been running it with the ABS fuse pulled and brakes work fine but dash light stays on. Car has only 64,000.
Expert:  GM Tech (Cam) replied 5 years ago.
This is a fault with the front wheel speed sensors. They are mounted into the front wheel bearings and after time and wet, the corrosion starts to slightly push them out and expand the air gap. Then at low speed, the signal drops off and the ABS thinks the wheel has locked up. Take the wheels and rotors off, use a 5mm hex wrench to remove the sensor, make sure the plastic is flat and clean all the corrosion off the hub. Install them and see if that helps.
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