Diff is about to Go

[Snowwhite]

This makes me wonder about all the people who have the "stiff brake pedal" issue and being unable to start the car because it's damn near impossible to press the brake pedal enough to start the car. Makes me wonder if they're using Auto Hold, park the car, turn it off, and it does something odd with the brakes/brake pedal causing the pedal to be stiff/difficult to press. I rarely, if ever, use the auto hold feature so I wouldn't really know. I personally don't trust electronics enough to put my safety at a red light in its hands.

the EPB use a small electric motor mounted on each rear hub to activate the rear parking brake shoes. No hydraulics are involved. A stiff pedal after an overnight rest is most likely due to a brake fluid leak somewhere that is eliminating the built up pressure in the system. the leak can also be in the master cylinder.

auto hold uses the hydraulics. It is disabled on powering off the car.

 

[bfglitch]

auto hold uses the hydraulics. It is disabled on powering off the car.

This is why I mentioned the Auto Hold and just shutting down the car with it enabled. Didn't think the stiff pedal had anything to do with the EPB as I know they're separate systems and the EPB is mechanical, not hydraulic. Only reason I mentioned it was because I've noticed when Auto Hold is doing what it's supposed to, when you hit the brakes while it's enabled and holding, the pedal is stiff (because it's doing it for you). I wasn't sure if while Auto Hold was holding, and the engine is shut down, it releases the regular brakes. But I'm guessing it does release the regular brakes since it automatically engages the EPB on engine shutdown.

 

[7Andrei7]

I've had the stiff brake pedal first time almost 4 years ago. It is an on and off thing and I don't have any hydraulic leak. Not sure why it's happening. Seems to be more noticeable when brake pads are approaching replacement.