Brake pedal won't depress when starting ('06 325i)

I have a 2006 325i with Steptronic- for the past several weeks, when I go to start my car and depress the brake, it either won't depress at all, or it just barely gives. Sometimes this just happens the first time I start the car, sometimes it happens all day. I've not been able to find any mention of this issue thus far-- anyone have this problem? Any insights or advice (meaning, do I have to proceed straight to the dealer)?

Does it require a lot of braking effort to stop the car when it's moving?

If it does, it could be a faulty brake booster. When you put your foot on the brake and start the car the pedal should sink slightly. If it doesn't then the brake booster might need to be checked out.

Thanks for the feedback, Ryan M-- it's only hard to depress when I first put my foot on the pedal and push the starter button. As soon as it starts (which is stilted because I can't press the brake down all the way), then the brake pedal releases and it's normal-- but before, it's like it's stuck- little to no give. Same when driving and stopping, no problems. It's only when I start the car. Frustrating.

with my 2007 335i coupe. Sometimes when I try to press on the brake pedal in order to start the car, the pedal resistance is as hard as a rock. At first I was not able to start the car but then I would just apply alot of force from my foot to the brake pedal and that would allow the car to start. After the car starts the brake pedal resistance goes back to normal. Weird.

My wife's just starting getting this problem in her 06 325i as well. I drove it last week and know exactly what you are talking about and dont know why either. I tried searching this forum with different word searches but couldnt find anything. We have yet not been able to start the car, but next time it is in for service I will ask.

Hi

I wondered if your dealer managed to rectify the problem where you could not start your 325i auto as brake pedal was stuck? If so what was the reason as I have same problem on 325i m sport auto 2006?
regards
Peter

It's a known service item. There was a bulletin on it out last year. It shouldn't cause any problems other than what you describe.

http://www.bimmerfest.com/forums/sho...=brake+booster

You're right- vacuum valve. I had my 30k service this week, and they replaced the vacuum valve and hose assembly 'as per bulletin'. Now it's back to normal.

Thanks for your feedback, everyone.

S

I agree this might be related to the cold weather. I had this happened to me today after it snowed last night. I had to press the brake pedal with so much force to get the car started!

My, 2007=335I has the same issue, but since I purchased my car used, its always been like that, I just assumed that because the car was not running that its like having no power brakes and hard to depress, but I just step on the peddle till it sinks a little and the car starts. except for a little extra peddle effort, I have had no starting issues. is this something that a competent. mechanically inclined person can fix them selves.

Hondo

http://www.e90post.com/forums/showthread.php?t=589753

thanks Usaret, that helped me know that it might not just be the check valve and it also helped locate the grommet, I just looked at it on my 335, and the place where its located and that might be a booger to get to, I am thinking if its the gromet that goes into the booster I might be able to pry the vacuum hose out and with a pair of needle nose pliers or the Hemostats I have, I can pull the gromet out, its getting the new one back in that will be the challenge. the grommet appears to be around 10 bucks, and the vacuum hose with the check valve is around 90, from southatlanta bmw parts on their web site, I wont try anything till I have the gromet in hand either. But I can push the peddle down with some effort and the car starts. so not sure its that big of a deal for me to worry about, I did start the car, turned it off and tried pushing on the grommet and I hear no hissing sound. Then I got back in the car about 10 minutes later and its easy to push the peddle down so I know there is a vacuum leak somewhere

Hondo

My '06 has had that symptom since I bought it December '08. Doesn't happen every time, but usually when it's been sitting in the cold for quite a while. Hasn't affected braking so I'm not worried about it any more.

I might just order the grommet for the fun of it, will give me a project to do

Hondo