Minor Emergency Brake Trouble! <E30>

[centuri@xxxxxxxxxxxx]

Hi all!  Hope everyone has had a good turkey day.  

I spent part of mine replacing the rear brake rotors on my 86 325es.  
After fighting all the bolts loose I finally finished up and took it out for a 
quick test.

Mild braking worked fine, no noise, normal stopping.  However when 
you start to put moderate/heavy pressure on the pedal, you hear a 
repetative *thunk-thunk-thunk-thunk* from the right rear.  The 
*thunking* is speed variable going from an almost solid tone at high 
speed (60+) and *thunks* once every few feet just before you stop.  It 
also gets louder as you put more preasure on the pedal.

The car still seems to stop normally, no apparent inordinate drag or 
throbbing, it's just that noise.  

I've re-checked that all the bolts seemed tight and even partially 
removed and re-seated the rotor on that side. I don't see any strange 
wear patterns, but I've only driven it about 5 miles in testing.  The one 
thing I did notice is that there is a *very* small cut into the pad holder 
(The part of the caliper assembly that doesn't have any moving parts)  
but I really can't see how this rotor could be cutting into it as that part 
is stationary and the rotor isn't any where near it.  

Nothing seems loose at all and I can't think for the life of me what 
could be causing this noise.  It has to be something fairly substantial 
as the *thunk* sound seems fairly forcefull.

The emergency part is that I have to have this car to go back to school 
on sunday and I'm not sure I want to go on the interstate with 
questionable brakes.  Any help would be appreciated!

Thanks,
Robert Phelan
Webmeister, St. Louis BMW CCA Chapter
http://www.stlbmwclub.com

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End of bmw-digest V9 #1651
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