Sticking Rear Brakes

M

mattp64

Member
With the recent cold weather, has anyone else has problems with their rear brakes sticking after using the handbrake?

Since about a week ago my rear brakes seem to stick even if the handbrake is only for a few hours. The coupe was standing for a week or so over Christmas, but i left the handbrake off and just kept it in gear. This doesn't seem to have happened before, even when we had cold weather this time last year.

Is anyone else having a similar problem, or could it point to something like a broken spring? The handling does seem a bit odd too.
 
This ALWAYS used to happen to my VX220 with the Handbrake on the rear disks, but never on drums.

Theres probably some moisture in there causing the innder drum surface to corrode a little. Id just drive 100 or so yards with the handbrake lightly on to help warm up the drum, expel some moisure and clean all mating surfaces. Doing this stops my HB from squeaking when getting out of the car for a while! (A common Z4 'trait') :oops:
 
Common problem when washing the car also. Water/moisture on the engagement surfaces causes a small amount of corrosion which forms a bond.
 
gannet I think you're right, I do apologise...

Think this clears it up... something in between:
http://www.z4-forum.com/forum/viewtopic.php?f=3&t=15338&p=226867&hilit=+brake+drum#p226867
I knew there was something behind the rear brake.
 
no apology necessary :thumbsup:

Im always learning new things about the car - why I love this forum so much :D

Was surprised that mrs gannet's brand new Mazda 2 Sport came with rear drum brakes though :o
 
Haha cheers PawnScarifice!! :D

The drums are the inner 'bell' part of the discs. :) Compare the depth of the rears and the fronts below... You can see the rears have an extra tier of depth. This is where the handbrake shoes are! They may look tiny, but this is all thats needed for a handbrake :thumbsup:

Rear
67.png


Front
23.png


Benefits of this system are their redundancy of cable/hydralic systems. Plus the added advantage that applying the handrake on a rear disc car after enthusiastic driving is dangerous. This is because as all the hot materials cool, they contract, making the mating surfaces loose contact - cue a rolling away car!! Supercars also use redundant handbrake systems usually, however usually a twin (smaller) caliper as it reduces rotational mass and looks much cooler ;)
 
By making this BMW deprivated us of the posssiblity to add low ET deep dish rims genre "ET 20 19x10 M3 replicas" (due to the huge rear rotors)for cosmetic purposes as well ass the possiblity to drift a curve using the handbrake... thanks a lot BMW... :x
 
My car had the same problem on Monday morning (-5 degree). I had to give more power to the engine (above 3,000 rpm) to get the rear right wheel unlocked. I hope I didn't damage the handbrake.

I knew I would work from home today because of the snow, so I did not use handbrake after the car was parked last night. It is true that the car has the same problem after it is washed.
 
If it does stick, its much better (read: more mechanically sympathetic!) to gently 'rock' the car to free the brakes rather than just trying to drive forward giving it more beans :)

You should be able to do this just partly raising the clutch a few times to free the oxidisation. :thumbsup:
 
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