2008 X3 3.0si 102,000 miles
At the end of a 3 hr drive I came to a stop and had to push extremely hard on the brake pedal to get the car to stop. I tried the pumping of the brakes while car is off then applied pressure to brakes as it was started and the pedal did give some. Looking for advice on where to start in diagnosing the problem. Don't have any other issues. Thanks
Sounds like a booster issue, check valve ext
jclausen is right. Booster is not doing it's job. You have three factors to look into:
1- Check that the vacuum pump to booster hose is attached and it isn't cracked. That's the easy check.
2- Vac pumps don't go out often on these cars but a failed pump would make the booster inoperable. However a vac pump going out TYPICALLY is a gradual deal, not a sudden one
3- The booster itself could be not holding vacuum anymore. But it's not a common issue on these cars.
I think the factor with the highest likeliness to be at fault is the hose being dry-rotted with heat and age and it developed a crack somewhere. That's just the more likely suspect, and easiest/ cheapest to replace. So I really hope this is the problem for you.
Good luck!
Took to mechanic and wants to replace vacuum pump to brake booster. Said it took a special tool that he didn't have but could order for $150. Not much experience with X3, (mostly with 325i).
Quoted estimate of around $1100. Sounds a little much. Is this difficult to replace? Anyone know of a DYI ? i can't believe it's that hard or expensive.
I believe the vacuum pump on the 6 cylinder is driver side in front of and below a little bit of the intake manifold, its driven off the back of the timing chain system. . It will be harder to replace than the v8 engines, which is quite easy.
Bookmarks