2001 Sierra Brakes Lock up after replacing Wheel hub assembly HELP!

[elguadas]

Hello all,

I replaced the the left front wheel bearing assembly on my nephew's 2001 Sierra 4.8 liter; the procedure was very simple and found no problems taking out the old one a installing the new part. I doubled checked my work and everything is where is supposed to go, including reconnecting the ABS wire.

The problem started next morning when coming to a stop the brake pedal pulsates like the ABS is being activated. The roads here in central Texas are very dry. This happens randomly during the first few stops in the morning, then it does not do it during the day, but each morning the same problem repeats.

I would like to help him fix this problem asap since he is leaving for college this Friday.

Cheers,

Jorge

[j cAT]

Originally Posted by elguadas

Hello all,

I replaced the the left front wheel bearing assembly on my nephew's 2001 Sierra 4.8 liter; the procedure was very simple and found no problems taking out the old one a installing the new part. I doubled checked my work and everything is where is supposed to go, including reconnecting the ABS wire.

The problem started next morning when coming to a stop the brake pedal pulsates like the ABS is being activated. The roads here in central Texas are very dry. This happens randomly during the first few stops in the morning, then it does not do it during the day, but each morning the same problem repeats.

I would like to help him fix this problem asap since he is leaving for college this Friday.

Cheers,

Jorge

since you have no abs light ,,,this is most likely the ABS sensor in the hub is too far from the sensor wheel...

with a meter you must have at least 350mv. to get the ABS circuit to operate properly

if you clean /file the hub seating surface of the ABS sensor hole,,this will allow the sensor to get closer to the toothed wheel..

use the voltage output when spinning the hub by hand,,to determine when your in the proper output range....you should check both sides as well...I had to do this a couple of years ago....the ABS comes on when braking at less than 5mph...this is the problem..

after I completed my repairs the sensor output was 480mv...or about a half volt..

don't break these sensors very expensive...