View Full Version : Why does my car run better after brake booster change?

09-21-2012, 09:02 AM
Hi Peeps,
My 2006 750li just had the brake booster and master cylinder replaced on the recall.
Prior to that it would idle and start kinda rough.
I had complained to dealer all to no avail.
They said it is normal !!!
Now after new booster all is well......does not make sense as the vacuum to the booster is supposed to be independent ...right????
Very confused....but glad.

09-21-2012, 09:17 AM
a car engine running is a vacuum .. it gets vacuum from intake if theres a problem with the booster

ie leaking vacuum (dead pedal) then theres a "vacuum" leak just as if you take the oil cap off and run the car i bet it would run just like it did before the recall you performed

09-21-2012, 09:22 AM
But...I thought these cars had a "Independant" vacuum pump source of vacuuum for the booster only !
Maybe wrong!:confused: