Tried the search, but got too many unrelated threads... so,

I was "testing" the brakes today, from about 30mph or so to a quick stop. I didn't "slam" on the brakes, but I did a quick firm push. As I reached the bottom of the pedal, I felt and heard a loud grinding metalic sound, very briefly before complete stop. I tried again at various speeds, and the same thing happened. BTW, sound was coming from the wheels, not the pedal.

My guesses:
1. That's what ABS chatter sounds like when it kicks in (I doubt it)
2. The nose dove down and hit the pavement (I really doubt it at that speed)
3. The brakes locked then slipped (not sure how this can happen)
4. The brakes locked and the tires slipped on the pavement (NOT!!)
5. Something broke

anyone have any good explanations? Stopping power and distance didn't seem to be affected.

Thanks,
Jimmy

 

#1 - ABS chatter is very apparent - you'll leave a mark like - - - - on the ground.
#2 - 911s don't nosedive very much at all.
#3 - This could happen - even with ABS, momentary lockup can occur.
#4 - Not likely.
#5 - Could be. Also could be loose lug nuts.

Have you check the pads? If the pads are worn down (or are close to worn down) you could be hitting the indicators to change them. It's a pretty loud screech on most pads I've worn down. You could also take your wheels off and inspect the wheels/brakes (check for gravel in the caliper)/hub.

Good luck...

 

That's just the pad material to rotor sound. It's even more pronounced with more aggressive pads, like the Pagid Oranges I have on now (I swap street to track and back). Just yesterday when I was out, I was trying to not "squeal" and pressed firmly and there was the metallic grinding sound that you can even feel slightly through the pedal (feedback). But under "normal" braking, no grinding - just slight squeal (no squeal on street pads).

 

Thanks for the feedback, guys! I can sleep at night now. I did have a 40 point inspection a year ago at the Porsche dealer when I bought my car, so I would hope they would have checked the pads... but I'll mention it again at the next oil change (in 4000 miles).

Jimmy

 

ABS chatter - happens all the time. Check you tire pressures as having them set wrongly seems to increase the likelihood that ABS will be activated.

 

Great pic, Jimmy! Love the crown on the little one...

 

Thanks, Don! Appropriate outfit, since he is now officially the King of our castle!

Jimmy