My new 2004 Silverado has bump in brake system at 11mph? You feel and can hear a loud vibration through the brake pedal. It only does it after startup upon initial acceleration always just at 10-11 mph. Currently at 3000 miles and has done it since new. Thanks.

No one's heard of such, eh?

It's your anti lock brake system doing a self test. It's normal.

My new 2004 Silverado has bump in brake system at 11mph? You feel and can hear a loud vibration through the brake pedal. It only does it after startup upon initial acceleration always just at 10-11 mph. Currently at 3000 miles and has done it since new. Thanks.

Check your rotors for oxidation or rusting, gm has gone to cheap inferior rotors on their trucks and when they sit on a car lot for a few months they rust and cause vibrations and noises, you may want to consider going with aftermarket rotors because you can expect to replace the stock ones around 30-40k.

It's your anti lock brake system doing a self test. It's normal.
Dealer said it's the brake assist motor. replaced it, now does it at 20-22 MPH. They said normal for those trucks equipped with it, yet not all Silverados have this item. Technician was unable to explain it very well. Normal or not, it's annoying and isnt present in my dad or brother's 03's. ALBS have been around a while, I don't understand why this self-test, assist motor, or whatever it is has to be so noticeable. I'm slowly regretting my new Chevy purchase.

I'm slowly regretting my new Chevy purchase.[/QUOTE]

Join the Club. GM has really disappointed me since I bought my Silverado.
I can't believe the trivial issues GM will not address with these trucks and just puts the "Normal for these trucks" stamp on it.
Next truck??????? Ford F250 :-)

I'm slowly regretting my new Chevy purchase.

Join the Club. GM has really disappointed me since I bought my Silverado.
I can't believe the trivial issues GM will not address with these trucks and just puts the "Normal for these trucks" stamp on it.
Next truck??????? Ford F250 :-)[/QUOTE]

I hear you, but trouble is I just dropped a 2001 F150 for this truck because it was out of warranty and had lots of issues. I'm gonna check out Dodge, Toyota, and maybe even the Titan if they calm it down a little on the appearance. Normal for these trucks....weak. My dad's 03 has 14000 miles and the front end sounds like its about to fall out...no off-road use. I like the Silverado appearance much more than other brands though.