2003 T6 AWD XC90

Two issues: just installed new rotors and brakes. Did it my self so worder it i miss a step? Now when i am driving 70% time once i take my foot off the brake i get a "hissing" noise until i tap the brake again. Brakes and rotors seem to be fine just the noise is very noticeable? It comes and goes but mostly comes. Any ideas.

Second issue: when i turn off the engine a 3 to 4 second burst of noise comes from a pump of some kind that is located under theengine compartment right behind the radator. It is labeled Pump UP28. I have only had the SUV for a year but never really noticed the sound until a couple of weeks ago. It goes on for about 4 to 5 min. It is not the fan running it is this small round pump? it is coiling the turbo's or something?

Befor i spend 300 bucks at the dealer to tell me it is normal i wanted to check.

 

I am having the exact same problems.

Just had an oil leak fronm the main seal fixed.
I got my 2003 XC90 back and the brakes now make a hissing noise when they are not depressed.

Also have an intermittant "buzz" noise coming from the right side of the enginewhen the engine is shut off.

Happens about every 10 sec or so. Mechanic says it is keeping the turbo pressurized? Don't know if I buy that but also don't know enough to question.

I have also noticed the steering is much tighter and creeking when wheel is turned while vehicle is stationary.

Took it back in today and will let you know what they say once they fix everything.

Would appreciate a reply from someone who knows anything about these (common?) problems.

 

YOUR SYMPTONS MATCH WHAT WE CALL A "BRAKE BOOSTER"