siyan

So I went on vaca for a week. My driveway is a bit sloped so I always use the parking brake.

When I got back the car had some vibration under braking. No big deal I thought, probably just rotor rust. Some of it went away in a few minutes but even a month later there is a substantial vibration left.

Obviously this is not the first time I've gone on vacation with the parking brake engaged...but I'm baffled as to why it would suddenly warp this time?

Does anyone know which side the ebrake engages?

Rudeney

The parking brake doesn't use the pads and rotors for holding. It uses a separate drum with its own brake shoes, but that drum is the center "cap" of the rotors. I don't see how the parking brake could warp the rotors, unless you drove with it engage and it overheated, but even then, I think that's a stretch. It could be that the parking brake system is binding and not releasing so you are getting vibration there, or it could just be coincidentally time for new rotors and pads.

siyan

Ah ok so it is separate. Good to know. I just had the pads changed a few months ago actually.

phingoc

try to press down the park brake pedal while driving so the shoes can grind away the rust on the inside of the brake drum..

eddieo45

This kinda happened on the 1999 Lexus RX300 I just bought my daughter, only worse. At the state safety inspection the parking brake "seized up," with the pedal releasing but the shoe still holding. After a fair amount of banging with a hammer it loosened up enough to drive, but I was left with that vibration you speak of. Ultimately had the rotor removed and the whole assembly cleaned and lubed (probably should have replaced the cable too). This Lexus likely hadn't had the brake engaged much over 14 years but yours might be stuck from LOTS of use, and need some love.

siyan

hmm but if my vibration only happens while braking, how could it be the parking brake binding? wouldn't that cause a constant vibration regardless of whether you're on the pedal or not?

Glyn M Ruck

Brake really hard a couple of times. Likely still some uneven rust/pad imprint on the rotor/s. Did you clean the wheels before going on vacation?

Glyn M Ruck

For further explanation. Benz tells you in your owners handbook to not use acidic wheel cleaners and to always take the car for a run after cleaning wheels to heat up the brakes & drive off all water & dry the pads. Failure to do this can lead to uneven rusting & pad imprint on the rotors. If you think that this has occured then follow the Stoptech bed in procedure here and/or lightly sand the rotors at 90 degrees to the rotary rotor wear.

http://www.stoptech.com/technical-su...-system-bed-in

Good luck!

siyan

Thanks Glyn. Sounds like it will require a rather long stretch of un-policed road to get it done optimally. I will have a think.