Occasional No Brakes at Low Speeds

[DavidSelf]

I have a 2002 Silverado and within the last year or so occasionally when you are coming to a complete stop, the brakes go to the floor and make a wining noise for the last 10 or so feet.  The truck is hardly driven the last couple of years but the brake lines and pads have been replaced within the last few years.  The master cylinder has fluid in the reserve tank.  Anyone deal with something similar?

[davester]

You might consider flushing both the power steering fluid (this is also used by the Hydroboost to assist in braking) and the brake fluid (it attracts water from the air and doesn't perform as well).

[CamGTP]

Sounds exactly like a wheel speed sensor dropping out as you slow down.

 

I've run into this issue many times before. If I was watching each wheel on a scan tool, in this case both front wheels, one of the sensors would drop out to zero mph as the vehicle is coming to a stop. It can cause the pedal to become really soft and the whining is the ABS pump.

 

If possible, get the truck hooked up to a nice scan tool that can do live data readings for each wheel and see if you can watch them as you start slowing down.

[Brian715]

My blazer used to do this.  Faulty wheel speed sensors.  Replace the hub assemblies.