10/27/2026
Stuck rotor with internal handbrake mechanism
Solved! The rotor was rusted incredibly hard to the wheel hub. The handbrake was fine and not stuck, even would have been without turning the adjuster. After spraying rust dissolver into every ‘gap’ between the rotor and the hub and hammering onto it without any hesitation, we got it off after another hour.
Thanks to everyone who contributed with suggestions and experiences!
TL;DR: Brake rotor with integrated drum-in-hat emergency brake is completely stuck despite hours of trying. Any advice is welcome!
Full story: Today we tried to change the brakes on a Mercedes A160 (W169, 2009 model) due to old age and constant noise.
I consider myself a decent DIY mechanic and just wanted to help out a buddy. The car has been sitting a lot, mostly outside, has relatively low mileage, so these brakes might still be factory original or changed once or twice at most. Needless to say, there was plenty of rust and almost everything was seized up.
Front brakes went smoothly, but we hit a brick wall at the rear: We took off the first rear wheel, removed the caliper & caliper bracket, and unscrewed the rotor retaining screw. But the rotor won't budge a single millimeter.
Our guess is that the internal handbrake (drum-in-hat system) is holding the rotor tightly onto the wheel hub. When the handbrake is engaged, nothing moves. When it's released, we can spin the rotor freely, so the mechanism basically works as it should.
We spent several hours trying everything to get that rotor off: hammering from all possible angles, trying to release the handbrake cable from inside the cabin to remove any residual tension (didn't work, the cable setup is built in a way that you can't loosen it without tearing apart the interior or underbody), trying to turn the adjuster wheel through the lug bolt holes with a small screwdriver, and spraying massive amounts of WD-40 inside (since the whole brake system is getting replaced anyway). We even spun the hub/rotor with a slightly engaged handbrake (first dry, then soaked in WD-40), pulled and released the brake lever rapidly, and combined all of these methods over and over for hours.
In the end, everything is just as stuck as before. The rotor is still sitting flush on the hub, it hasn't moved forward a tiny bit, nor did it twist. The hub is still perfectly aligned with the rotor. It feels like we are missing a bolt or some kind of connector, but we are absolutely clueless since we double- and triple-checked everything.
After all this wrestling, the whole assembly can still be spun by hand with the handbrake moderately engaged (and lots of WD-40 inside) if you push hard enough. However, when moving it back and forth, we can hear clicking/clacking noises (I can share a video of this). Does this indicate a defect or the root cause of our problem, or is that normal?
How do we get this thing off? Radical suggestions are highly appreciated, everything is getting replaced anyway! The car is currently parked in our employer's parking garage. Using an angle grinder might be possible, but only as an absolute last resort. Ideally, we need to get this solved and fixed tomorrow. Thanks in advance for any help!
