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      11-06-2011, 09:57 PM   #71

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Drives: 2013 E70 X5d Swiss Army Knife
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Originally Posted by lve2xlr8 View Post
There is another noise that typically happens within the first couple minutes that sounds like it's coming from the front driver's side fender. It's almost sounds like a power mirror motor but is only on for about 5 seconds, what is this?
I believe this one is the brake booster using a pump to
pressurize the brake system fluid in the lines.

There is a noticeable correlation between front brake pad wear/thickness and how long that pump operates on startup.
Dave Flogaus CCA #123862
Instructor, BMW Club Racer & Nürburgring Specialist
95 E34 M5 3.8 Daytona Violet
98 E36 M3/4 White IS #244
14 F31 M Sport Touring, 13 E70 X5d