I have a '98 GMC Sierra 1500. I really like this truck...the way it runs (!!!), the way it looks, no complaints! BUT, when I am braking, I feel pulsation in the brake pedal. Some have said the ABS does that, but I am wondering if I have a warped rotor. I bought the truck with 39,000 on it, and I don't recall it ever not doing this. Yeah, yeah, I know---I shoulda noticed when I test drove it, but that's water under the proverbial bridge.

Thanks in advance!

GM has had alot of problems with brake rotors warping and rusting. With your kind of mileage it would be a safe bet that the rotors need to be cut! ABS you would feel it in the brake pedal and it would be a real fast pumping action.

Mmmm...I think I understand, Flatrater. I have felt the anti-lock operate before, and I think you're telling me that if it was the ABS doing it, it would be pulsating at the same rate as when the thing goes into anti-skid mode. Come to think of it, it makes sense that the anti-lock does its thing at the same rate ANY time it is active. Am I on the right track?

I'll pull those rotors and take them to town to be turned.

Thanks!

Being in the autoparts bussiness, turning rotors can be a cheap fix, but consider this. When a rotor is turned, you are effectivley taking away friction material from the rotor making it thinner and thinner and not neccessarily preventing future warpage. Turning rotors can cost up to $20.00 each where a new rotor cost will cost starting approx. $35.00. How much is your life worth to you?

Think about it.

Where do you find $35. front rotors for a GMC truck ?? Even offshore ones cost more than that.
And the easy test for the anti-locks ?, is just unplug the anti-lock motor and if the pulsing goes away, then it ain't the rotors.Good luck.

Sorry guys I just realized how old that thread is, ignore at will.