Thudding/Clunk while braking

[BMW_Hatchback]

(FYI) Front setup: E36 M3 Rotors/Brembo calipers

Symptoms:

* Sound of friction when in motion coming from driver's side front brake.
* Clunking: Loud & hard clunking/knocking when braking to a stop felt to the left of my feet (towards the brake of course). The clunking feels like a tumbling brick coming to a halt. It's a very aggressive pulse.
* The steering wheel jerks hard w/ the clunking
* In another thread, someone said it can feel like ABS kicking in HARD
* With the wheel off, there is inconsistent resistance when trying to spin the rotor by hand.
* When I press the brake at a stop, I hear a metal low pitch squeak/groan coming from the front brake.
* When coming to a stop, when I press the brake I hear a single click coming from under the chassis exactly when I press the brake.
* The rotor is visibly pretty corroded, but nothing unusual IMO.

More in depth observation:
I hear friction coming from the front driver's side brake when the car is in motion, which turns into hard clunks and thuds when braking to a stop. I didn't move the car much over winter, but before then the brakes were fine. I'm leaning towards a stuck piston, but I don't know if the car sitting in the driveway for 2 months would have caused this.

Some relevant threads I stumbled upon:

http://forums.bimmerforums.com/forum....php?t=1436349

http://www.318ti.org/forum/showthread.php?t=32435

major eye sore right now:




I'm thinking a stuck piston

[familytruckster]

caliper sliders might be worn and all that rust on the rotors could be causing the issue.

[spidertri]

lcabs?

[tiFreak]

are the pads on the other side worn down to the same level?

[BMW_Hatchback]

here is more info from my thread on bf.c http://forums.bimmerforums.com/forum...9#post21887839

Other people might want to see and hear what I'm trying to describe for their own records, or if anyone had something similar so here it is.
the main parts you hear the clunking is @ 00:30, 01:15-01-20, and 02:05 (ignore the crazy spanish girl yelling at whoever)
http://www.youtube.com/watch?v=1H_drBdvrBU

flyfish I'm going to go do what you said

Originally Posted by flyfishvt

Im thinking you've got a brake pad that isn't traveling all the way back with the piston. You have a pretty bad build up of rust on the rotor so you could have some rust or corrosion on the part that holds the pads.

I would take the whole thing off, clean it up, lube it properly and try again.

Take a 3M scrubbie pad to that rotor or the rust will imbed itself in the pads.

[quote]Thank you for your solid advice. I'm on the same page of thinking as you. I'm just having trouble connecting how any of the potential issues would have happened to a car that was parked for two months.

And another thing, the rotor on the other side had rust on it before, but all of it is gone since I drove it this week. That rotor is shiny as it should be, this one remains dull and its pointing to the pad like you said.[quote]

I also took a video of the noise it makes when parked with pressure on the brake.
see it here http://www.youtube.com/watch?v=Z0CtFTJ6VbQ

[1996 328ti]

I installed solid guides and developed that problem.
I think it's a stuck caliper pin.

[BMW_Hatchback]

Originally Posted by 1996 328ti

I installed solid guides and developed that problem.
I think it's a stuck caliper pin.

how did you resolve your problem?

[1996 328ti]

I reinstalled the stock bushings.

[BMW_Hatchback]

I separated the caliper from the rotor and greased them, put them back on. Still no improvement

[cooljess76]

Originally Posted by BMW_Hatchback

I separated the caliper from the rotor and greased them, put them back on. Still no improvement

I'm thinking you have a stuck piston Ced. You should take the caliper back off, remove the pads and give it one light pump. You should see the piston extend a little. At first I thought the little rust on the outward side of the rotor could've formed in a couple hours if it's wet where you're at, however if you say it's rusty even after driving, the pads simply aren't making contact. You should try bleeding that caliper first, maybe there's just air trapped in that corner. I like to use a clean soda bottle with a clear hose so you can see if air bubbles are coming out. Just make sure the hose is submerged in brake fluid as to not suck in air bubbles. If bleeding it doesn't help, it's time to rebuild your front calipers. Best of luck broham.

[BMW_Hatchback]

Originally Posted by cooljess76

I'm thinking you have a stuck piston Ced. You should take the caliper back off, remove the pads and give it one light pump. You should see the piston extend a little. At first I thought the little rust on the outward side of the rotor could've formed in a couple hours if it's wet where you're at, however if you say it's rusty even after driving, the pads simply aren't making contact. You should try bleeding that caliper first, maybe there's just air trapped in that corner. I like to use a clean soda bottle with a clear hose so you can see if air bubbles are coming out. Just make sure the hose is submerged in brake fluid as to not suck in air bubbles. If bleeding it doesn't help, it's time to rebuild your front calipers. Best of luck broham.

Thanks Jess, I'm going to go ahead and do that friday. I fear only one pair of the four pistons are not engaging and/or disengaging. This may call for a rebuild of the caliper, and definitely a new set of rotors is definitely needed.
E46 floating rotors aint cheap tho