All new brakes, slight pulsing and soft pedal...?

[derekjl]

So we just had the entire brake system replaced on our '99 Tahoe with 120k miles on it. Parts included the front calipers, pads, hardware, discs, rear drums, shoes, etc. The only OE parts used were the front pads, everything else was NAPA (maybe the first mistake?). I should also add that the service was done by the highest rated shop in my area, which also happens to be an AC Delco service center. So, I was surprised when I first drove the truck that the brake pedal had become softer than before. Under really heavy braking the pedal can damn near hit the floor. I also noticed that when slowing down from highway speeds there is a pulsating feeling. Not necessarily in the brake pedal, but in the seat and possibly from the rear? I've heard that brakes need to "bed in", but someone please explain to be what could possibly be going on. There was also a noticeable "metallic" smell after driving the first few times as well. It's the same smell you notice from a brand new car. Thanks for any help!

 

[livingez_123]

New pads can often smell until fully seated. Have you talked to the repair shop? That would be my first stop, it's in their best interest to solve your problem.
Some NEW drums can be out of round right out of the box, wouldn't surprise me if it was a bad drum. The shop might have done bad job of bleeding the brakes. Even in good shops, mistakes can happen.

 

[SunlitComet]

well it sounds like either defective or inferior parts or the new parts got overheated and damaged something. go back to the shop.

 

[BRUTUS_T_HOG]

I can't even count how many napa brake drums and wheel cylinders I have had be BAD straight out of the box. It got to the point I would have to turn them on the lathe out of the box to prevent pulsation.

Your soft pedal kind of sounds like somebody didn't get the new drums/rotors clean before install. The rotors/drums usually come coated with oil. I have also seen severely overheated brake pads cause a soft pedal.

Start by taking it back to the shop, if they care about their rep they will take care of it.

 

[NGAneer]

Had a pulsing after machining rotors on my old truck. They were reinstalled with new power stop evolution pads. I was worried that the machining was off (had an older guy do It out of his old race shop locally, $20 for all 4). Turns out the pads just hadn't seated well yet. After a week or so it was good for another two years until I sold it.

 

[SunlitComet]

one week? I had my hawks set in less then an hour.

 

[NGAneer]

That's what I remember. Could've been less, like I said it's been a couple years. I do remember a little shutter or pulsing when running 55 and lightly applying the brake coming up to a stop light. That I know was there when driving it to work after the weekend install. Even if it was a week, it went away and that truck stopped like crazy (for what it was) up until I sold it.

 

[mattluttrell]

I do the "bedding" trick when I do new pads and rotors. I just go from 55 to 0 very quickly a half dozen times.

I'm not sure if it does anything but it is fun. My brakes always work well too.

Edit: pulsing could be bushing issues too.