Audi brakes dragging

[Daniel Stevens]

E. Roy

think of the brake hose as an artery. 
still capable of holding pressure and allowing fluid movement
but broken down and swollen on the inside. brake fluid is very nasty stuff, and even rubber designed for contact can and do fail

the 'clogged artery' allows high pressure to pass thru in one direction but residual pressure (~4psi) can't force it's way back 
in humans this leads to stroke/heart attack 
in audis smoking brakes on only 1 wheel.   a MC problem though just as real will effect pairs of wheels.
although individual calipers in that pairing may have differing effect. based on wear and conditions.

not discounting your MC theory/problem just reinforcing my hose issue. in the last 18 months i've had this hose issue on 4 of my&family vintage cars. and in each case replaceing the hose quickly ammended the issue. 1st car was the toughest diagnosis, 
after changing the calipers, MC, and still having 1 smoking hot brake. in this case car was a 1966 type 343 VW ghia. 

my advice is change the hoses before the MC, cheaper and easier, probably good maintenance as well. 
thanks for the reply, and the heads up on MC issues. I've usually onlyhad a MC pass w/in it's self ie. no pressure to brakes when failed.
dan 
1987 audi 5000 CS turbo quattro
1987 vw syncro vanagon
too many vintage VWs to count

>>> "E. Roy Wendell IV" <erwendell at mac.com> 4/4/2006 9:22:20 PM >>>
Actually, the dragging breaks is a symptom of a bad master cylinder.  
When the master cylinder is cold they will release just fine. But if  
you sit still for very long or the ambient temperature is high, the  
master cylinder will heat up and stop releasing all the way and the  
brakes start dragging. BTDT twice. The diagnosis is easy to confirm.  
Drive the car until the brakes start dragging, pull off the road,  
loosen the brake line fittings at the master cylinder to relieve the  
pressure, and watch the problem disappear until the next time you  
touch the brake pedal. Search the archives if you don't believe me.  
Seriously, I don't know where the whole collapsing break line thing  
got started. The very idea defies the laws of physics.

BTW, I responded directly because I didn't want to clutter up the  
radio thread with brake info. If you want to discuss this issue on  
the list feel free to start a new thread.

E. Roy Wendell IV
erwendell at mac.com 
Too many type 44 tq
A pair of MR2s