Break Pedal Heavy AIR RELEASE SOUND!!!
02-13-2019, 02:45 PM
#1
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C43
Break Pedal Heavy AIR RELEASE SOUND!!!
Hey guys, just bought my 2017 C43 has super heavy air release sound after pressing break pedal. The sound came out when my foot is off the break, it will have the zizizi sound which really drive me crazy.
Is this normal to Benz?I took to dealership they told me it is normal, they cannot fix that.
Thanks!
Is this normal to Benz?I took to dealership they told me it is normal, they cannot fix that.
Thanks!
02-13-2019, 03:13 PM
#2
I had mine checked because I thought it was the brake booster (as per many who have the same issue). The techs confirmed normal operation of the booster and that the sound was the atmospheric release valve (which may be louder when it's cold out).
02-13-2019, 06:07 PM
#5
Member
My car started doing it about a month ago when it got really really cold here. It’s not as pronounced on the “warmer” days, I just assumed like everything that is subject to extreme cold, it would or will go away once weather breaks. It sounds like we all have similar experience so it must be normal? I haven’t noticed any perforce difference in my brakes.
02-14-2019, 01:25 AM
#6
Senior Member
Yeah, unfortunately that's "normal". Someone once asked me what that wooshing air sound was and I very proudly thought they were talking about the turbo blowoff. Yeah...they weren't. They were talking about the fact that it sounds like some is using a manual air pump to fill up a balloon every time you let off the brake.
02-14-2019, 02:40 PM
#7
Our 2007 E350 has the "brake by wire" brake system that I'm assuming is equivalent to our C43. The E350 (and I assume the C43s) do have a mechanical brake-booster setup. The MBZ WIS/tech docs for the E350 explain this is for two reasons; 1) to provide normal brake "feel" and 2) to function in the event that both the primary and fail-over "bake by wire" circuits fail (so you don't break anything if your brakes break?). Again, I'm assuming it's the same in our C43s.
I'm pretty sure the "whoosing" sound is coming from the brake-booster mechanism. Our E350 does it, also.
OTOH, it may be an issue if it's too pronounced:
https://mbworld.org/forums/c63-c63s-...ase-sound.html
I'm pretty sure the "whoosing" sound is coming from the brake-booster mechanism. Our E350 does it, also.
OTOH, it may be an issue if it's too pronounced:
https://mbworld.org/forums/c63-c63s-...ase-sound.html
Last edited by user33; 02-14-2019 at 02:42 PM.
