[cayree19]

I have a 2007 E70 V8 that I've had for less than 6 months. 170k miles. The power brakes are basically non-functional now. When we first got it, they worked most of the time. There was the occasional stiff pedal on a downward incline, but not all the time. The problem has gotten progressively worse, and now they basically don't function at all. When the pedal is pressed, you can hear the vacuum leak. We took it to the dealer because of the recall and were told the recall had already been completed on it, so they won't do anything. We have 2 other e46's and have done extensive work on them, but never messed with the brakes much. How can we tell if the booster is the problem? If the booster is the problem, I am confident we can change it, but how do you bleed the brakes without taking it to the dealer? We can drive it, but stopping it without power assist is difficult. Please help!

 

[FredoinSF]

I have a 2007 E70 V8 that I've had for less than 6 months. 170k miles. The power brakes are basically non-functional now. When we first got it, they worked most of the time. There was the occasional stiff pedal on a downward incline, but not all the time. The problem has gotten progressively worse, and now they basically don't function at all. When the pedal is pressed, you can hear the vacuum leak. We took it to the dealer because of the recall and were told the recall had already been completed on it, so they won't do anything. We have 2 other e46's and have done extensive work on them, but never messed with the brakes much. How can we tell if the booster is the problem? If the booster is the problem, I am confident we can change it, but how do you bleed the brakes without taking it to the dealer? We can drive it, but stopping it without power assist is difficult. Please help!

The dealer won't do anything? I find that surprising. Will they not do anything because you are asking them to replace the parts involved in a completed recall at no charge and you won't authorize a diagnostic? If so, can't blame the dealer.

Regardless, that thing should not be driven on public roads with brakes behaving as you describe. My next step would be to get the thing towed to a different dealer or to a independent BMW mechanic for diagnosis. List of BMW mechanics for your area can be found at Bimrs.org or bimmershops.com. I suggest cross referencing Yelp.

You can bleed brakes without going to dealer. BavAuto.com likely has a how to video, and there's always YouTube. The fact that you are apparently not aware of that reinforces the need to have a pro diagnose the other issue.

 

[cayree19]

I am not interested in having the dealer diagnose the problem for me and charge me for it. That's why I am posting on here. Has anyone else experienced the same problem and can point me in the right direction? It does not need to be towed anywhere. The brakes work, they just require more force to stop than with power assist.

 

[ard]

I just dont know what to say....there are a huge number of things my stubborness would mandate that I not use the dealer. But BRAKES?! Really? I know how to fix them, you are clearly clueless- but you'll refuse a diagnostic?!?! (never mind that somehow you think the dealer owes you something for free- on a massively used 7-8 year old car...)

BUT...

Im going to guess that the booster has progressively gotten water logged as the water drains around the cowling/behind the engine have become blocked.

My no-cost guess from here.

 

[Doug Huffman]

I was astounded on discovering the size and depth of the well that the brake master cylinder and booster is fitted it, and immediately thought of the consequences of flooding that well. It is on my list of regular checks, along with the rear left and right electronics compartments.

Is there no drain for it? Do other options use the space/volume?

I wonder, is OPie's vacuum pump working properly?

 

[FredoinSF]

First post:

{SNIP} The power brakes are basically non-functional now. {SNIP}

Then I gave you advice you did not seem to care for and come back with this:

{SNIP} The brakes work, they just require more force to stop than with power assist.

Pardon my confusion but which is it??

It's very likely brake booster related, but as far exact problem and how to fix it I'm out.

That being said my recommendation to not drive and tow (or fix before driving on public roads) stands. You have a car with brakes giving you clear indication of failure. As someone who has worked with insurance companies, collision reparairers, as well as auto recyclers for nearly 25 years. I regularly am called on to go look at cars that are so mangled they are practically unrecoginiable knowing how many did not make it out and with bio matter still there. I find your casual approach to brake failure absolutely revolting. I'll get off my soap box, but please don't insist that it is OK to drive as is and get the thing fixed.

 

[528JD]

I have a 2007 E70 V8 that I've had for less than 6 months. 170k miles. The power brakes are basically non-functional now. When we first got it, they worked most of the time. There was the occasional stiff pedal on a downward incline, but not all the time. The problem has gotten progressively worse, and now they basically don't function at all. When the pedal is pressed, you can hear the vacuum leak. We took it to the dealer because of the recall and were told the recall had already been completed on it, so they won't do anything. We have 2 other e46's and have done extensive work on them, but never messed with the brakes much. How can we tell if the booster is the problem? If the booster is the problem, I am confident we can change it, but how do you bleed the brakes without taking it to the dealer? We can drive it, but stopping it without power assist is difficult. Please help!

1st thing you really need is a good Indy mechanic.
2nd, the following parts will be needed:
a. Booster vacuum pump
b. power brake booster
c. brake booster seal
d. booster vacuum pump seal
e. brake master cylinder o-ring
you can find them from any of our sponsor sites, or others.
about $1,000 in parts

good luck.
note: driving it the way you've described is dangerous. Having to "stand" on the brake pedal to stop isn't something you'll be wanting to do much longer.
I went through this near exact scenario a months ago.
:thumbup: