Front thumping noise while braking

Doc_Oc

Veteran Member
Joined
Feb 22, 2005
Location
Orangeville, Ontario
TDI
03 Golf TDI
I just upgraded my spindles to 1.8T along with new rotors, pads and wheel bearings. So, only the spindles, carriers and calipers are used.
The first 2-3 brake cycles are ok, but as soon as the brakes warm up, they develop a thud-thump rhythmic noise, wheel speed dependent.
I visually inspected the rotors and pads (removed from the car) and can't see anything abnormal.
The hub is not touching anything (at least that I can see).
I need some ideas!!! :)
I will swap rotors and pads from side to side, also, I will swap the calipers guide/carrier pins.
I think the sound comes from the driver side, although it's not very obvious.
Can a rotor be cracked? (Brembo rotors) As I said. It only makes the noise after it heats up. And the more it heats up (the harder and longer you brake) the louder the noise gets.
Not being able to see any defects on the pads and rotors, my only guess right now is that one of them (which one?????) has a fine fissure that expands when heated and that's what makes the thud noise.
Anybody experienced something like this before?
I can't even call the shop I bought the rotors and pads from and ask for warranty since I am not sure what is broken:)
 

Doc_Oc

Veteran Member
Joined
Feb 22, 2005
Location
Orangeville, Ontario
TDI
03 Golf TDI
Swapped the rotors from side to side. It was ok for 15 kms. Now it's doing it again.
Maybe even harder. I can definetely say it's on the driver side and now I can kinda feel it in the steering wheel.
Can it be the caliper guiding pins?
Can it be the hub? Cracked or bent or somehting? Although I can't see anything.
As I said, it's a brand new bearing. The inner cv is brand new. And it made the noise before I changed it and the bearing. I don't see anything touching anywhere.
The outer CV has maybe a bit of play, not more than the other side, and it doesn't click in tight turns.
Ball joint and tie rod end are not new, but they still have a few months left in them.
And what throughs me off, it doesn't do it on cold brakes. They have to warm up. 2-3 cycles and pretty aggresive. If they cool down, I need to warm them up again to get the noise.
 

Doc_Oc

Veteran Member
Joined
Feb 22, 2005
Location
Orangeville, Ontario
TDI
03 Golf TDI
Well, I will answer my own question :)
It turned out to be rust on the hub and some kind of oxidation/corrosion on the alloy rim.
 
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