CaprichioArabe

Hi all
I have a 2019 E450 Wagon that I bought new in April. It has been flawless until this past month when a few times the parking brake did not want to release when backing out of my garage. At first I thought it may be due to ice, but yesterday was very warm. The car would not go forward or backward until I finally gave it more throttle than I would like. Then it releases with a bang. It has only happened about 3 times. I’m wondering if there is something that I can check, rather than bringing it in to the dealer. Thanks!

xrayted

Were the wheels wet when you put the car in park? Had it recently been raining or taken through a car wash?

Same thing happens to me when I come home from work and it has been raining heavily and/or the wheels are wet (from a car wash) and then placed into park.
The following morning, the parking brake feels stuck until you give it just a little throttle to "unstick" the wheels. The banging sound it makes is rather alarming!

CaprichioArabe

Hi xrayted,

Yes, I think they may have been wet when parked. The first time it happened was after a very cold day, but we had over 12 hours with temps above 60F when it last happened. Hmmm, so maybe it is not actually the brake, but something else that is freezing to keep the wheels from turning. I think the bang sound comes from the front end.

ncdoc

It is most likely the pads lightly rusting to the rotors due to moisture. Some cars are prone to it. My Nissan GTR does the same thing after every washing.

TPAbnz

Same here. Sometimes when I park, the parking brake sets; other times (parking in the same place) it doesn't.
I can't find an answer as to parameters that make the brake set on its own.

ua549

AFAIK the parking brake always sets when the car is in park and the engine turned off. It is difficult to feel/hear the brake release during normal operation. My brake will stick sometimes after washing the car. When it releases one can definitely feel/hear it release.

CaprichioArabe

I have always set my parking brake whenever I park, but never had this issue. What is different about this car compared to my wife’s GLC 300 or my previous cars (like my E550) that it freezes up? And is there a way that we in cold climates can prevent it? I’ll contact the service folks when I get a chance.

adityab

I asked an MB tech about this. Says it's a peculiarity of the design, and recommends releasing it manually before starting off.

CaprichioArabe

Thank you. I appreciate that you inquired. I believe that I do manually release the brake, unless I’m not using the switch properly. It’s always been an unconscious habit from driver-ed days. I’ll have to pay more attention next time.