Help with identifying component in engine bay

[helicase]

I would like to know if someone can help me with identifying a component to my XC70 2,5T 2003. It´s located in the engine bay under the airfilter on the left side of the engine. Follow the link below to see it (marked with a question mark). Is it a motor for adjusting the xenon lights or perhaps a supplementary pump for the brake booster? Anyway, this component makes some periodic noice when I turn the car off.

http://i1035.photobucket.com/albums/a431/polymerase/Volvo%20XC70/Bild1.jpg

[jda2000]

that's the vacuum pump for the brake booster.

Is there a hiss under the dash by the brake pedal?

[helicase]

I can hear a hissing sound primarily when I release the brake pedal. The periodic noice from the vacuum pump is described earlier by me:

http://www.youtube.com/watch?v=BBXNjhp57WI

What would you think is the most likely alternative (add more alternatives if you have some ideas) ??

1. Leaks in the piping/connections to the vacuum pump.
2. Brake booster needs to be renovated/exchanged.
3. Or is the vacuum pump itself working normal but needs to be exchanged due to "abnormal" noice.

[jda2000]

I believe you have a vacuum leak between the pump and booster.

Check the hoses attached to the vacuum pump for breaks, loose connections. Also check the hose connection at the check valve at the booster.

If these are fine, then I suspect you have a leak at the brake booster itself :(, thus the hiss at the brake pedal.

The pump is coming on because of the vacuum leak.

[RockitShip]

Yes, double-check all hoses to and from the pump as well as the brake booster. I replaced all of my hoses in my car, along with brake booster hose with new silicone ones (hose kit from "hose techniques" if I recall).

[dyerkes]

I have the same issue with that unit. It continues to operate for about 5 minutes after my car is shutdown. I believe it is s vacuum pump for your brake booster, but I'm still trying to confirm it.