Rear brake noise under hard braking

NickBeek

Veteran Member
Joined
Jan 9, 2011
Location
Upstate, SC
TDI
2013 Passat TDI 2006 Dodge Ram
Recently I had to stop very quickly from about 60mph. The brakes on my car are great and it stopped in the space I had no problem. The only issue was a strange noise from the rear. It was sort of a grinding noise. I only have around 12k miles on the car and the dealer did not say anything at my 10k service about brake wear. Under normal braking conditions everything is smooth and quiet. All my rotors look to be in excellent condition with smooth but not glazed surfaces, and no signs of overheating. The only thing I could think of was maybe it was the ABS functioning, but there was zero feedback in the pedal. All my past vehicles (American) give some feedback through the brake pedal when the ABS is doing it's thing. is this typical on German cars as well? Any input is welcome.
 

TDI_Timmy

Veteran Member
Joined
Feb 13, 2011
Location
Seattle
TDI
2012 JSW, DSG, Pano
The only thing I can think of is that it was the ABS doing its thing. The only other car German made car that I had to make a emergency stop in was a 2008 or so BMW 3-series. I don't recall a lot of pedal feedback - pulsing back up into the foot - like I have experienced on some American cars. Another car I have more experience with is a '91 350SD and I don't think the pedal vibrated much under emergency type braking that would engage the ABS system.

Other thoughts - excess brake dust that was trapped between pad and rotor during the heavy braking causing the pads to kind of skip over rotor causing the vibration which could sound like a grinding sound. A rock (or other solid foreign material) caught between pad and rotor? Possible but I would say it probably isn't because I would think that it would be making the sound all the time.

Have you talked to the dealer about it to have it checked out?
 

NickBeek

Veteran Member
Joined
Jan 9, 2011
Location
Upstate, SC
TDI
2013 Passat TDI 2006 Dodge Ram
Thanks for the feedback. I'm fairly sure there are no rocks stuck, and amazingly enough this car produces almost no brake dust that is visible. Before I get the dealer involved I want to rule out the obvious. I think my next step will be to find some sandy or gravel covered road so I know the ABS is functioning and compare how it sounds.
 

TDI_Timmy

Veteran Member
Joined
Feb 13, 2011
Location
Seattle
TDI
2012 JSW, DSG, Pano
I don't think it would take much dust, and it would be dust that might be built up on rotor or pad and hasn't burned off because the brakes haven't gotten hot enough. Also not saying that this is the cause.

I also haven't noticed much brake dust from my car too.

Definitely find a place that you can go about 30MPH or so and get half the car on dirt/gravel and the other half on pavement - this way you force the ABS to work. Just keep it in control.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2017 Alltrack SE; Totaled 2015 Passat SEL, BB 2010 Sedan Man; 2012 Passat SE w/ Nav,
how's the PB adjusted? is it too tight? You should have 3-4 clicks before any real resistance. If it's tight on the first click, yank on it so you get about 5-7 clicks, this will stretch the cable out to where it should be. Alternitivly you can adjust the PB but that's a pain.

BTW the pads on these cars (at least my 2010) create almost no dust, i didn't even thinking of cleaning my wheels until 20K was on the clock.
 

NickBeek

Veteran Member
Joined
Jan 9, 2011
Location
Upstate, SC
TDI
2013 Passat TDI 2006 Dodge Ram
It was a little tight when I first got the car but I live on a steep hill. It is several clicks to hold the car now.

I still plan to find some sand and see what sounds and feel are with the ABS working.....
 

anotherTDI

Veteran Member
Joined
Mar 13, 2011
Location
st pete FL
TDI
2013 Passat TDI SE DSG, 2014 JSW TDI DSG
if you jam on the brakes really hard and sustained there is a noise that emanates from the rear of the car but i don't think it is the rear brake discs per se. and i mine doesn't sound like a grinding noise. to me is sounds more like a rapid pulsation associated with anti lock braking. i just assumed there is a anti lock mechanism in the rear of the car somewhere and that is what i was hearing.

be interesting to see what this turns out to be.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
Most likely it was the ABS cycling. Under hard braking, the ABS pump makes some weird noises, almost a grinding noise. VW rear brake pads wear fast, but 12k would be about 3 times faster than the usual fast-wearing brakes.

VW models have put more load on the rear brakes for a few generations now, so even under normal braking, the rears are doing a good chunk of the work.

If there no noises under normal braking, the pads appear to have a lot of material on them, the rotors are not rusted and/or glazed, I wouldn't be too worried about it.
 

NickBeek

Veteran Member
Joined
Jan 9, 2011
Location
Upstate, SC
TDI
2013 Passat TDI 2006 Dodge Ram
Mayor, I'm leaning towards your train of thought as well. I'll update as soon as I find a safe place to test the theory.
 
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