ABS pulsating when almost stopped

[KyRob]

I have an 04 sierra 4x4 xtended cab and the ABS system pulsates when I am just about stopped but only when I am stopping slowly. If I have to really get on the brakes it never does it but if I am kinda coming to a rolling stop applying very little brake it does it and it will do it when applying the brake and turning when going slow. By slow I am meaning less than 5 mph. I just today put on new pads and rotors and everything looked good except for the left front wanted to drag a bit after the repairs were made. There is no abs light coming on or anything just the pulsing pedal that you can feel and hear. Anyone have any idea what may be causing this? I read once that there was a sensor that may be dirty but have no idea where it is located. Truck still stops but it is aggravating.

 

Thanks in advance for any ideas,

Rob

[ed c]

Have you checked your front wheel bearings?

[KyRob]

The wheel bearings appear to be fine. There is no movement in them but I have no hi tech way of checking them. Just grabbing at top/bottom and side to side and working them. No movement can be seen or felt.

 

Thanks,

Rob

[oldscsc]

Check your wheel speed sensor connections. There was a TSB (or a recall) on this..corroded WSS connectors can lead to the symptoms you are describing.

[Vortec-Z71]

I had the same problem. It is your wheel speed sensors that go into the hub.

[KyRob]

What did you have to do to the sensors, clean them or change them out ?

 

Thanks,

Rob

[johnnyelohssa]

I know a few other people that have had the same problem.

You might be able to get away with cleaning the sensor.

[KyRob]

Thanks, I'll give it a try and see what happens.

 

Rob

[yukon25008.1]

Mine does it.. im swapping the hub and abs sensor

[mattymax]

Mine did it on my 02. I replaced both front hubs which has the abs sensor incorporated into it. Gm hubs were $600/piece back in 07. Prob more now

 

The sensor is covered on the new design. Where as the factory ones the sensor gets road grime and salt on them making them malfunction.

[yukon25008.1]

You can find Really good hub assemblys on ebay 'timken' for around $200 each.