Vacuum line problem?

I just purchased a used Acura 2.5 TL. During the test drive, we noticed you had to really push down on the brakes to slow down. Nothing dangerous, the brakes worked fine, but there was some faint hesitation. A 3rd party mechanic who evaluated the car for us before we purchased it said that the rotors wpuld eventually need to be replaced as they were rusted, but other than that, the car was in excellent running condition. The owner then showed us a receipt from 2008 that showed the front rotors were replaced in May 2008. Then, on the ride home, we noticed a high pitched noise that would be loud and then trail off, mostly when braking after driving on the highway for awhile. But eventually, the high pitched noise would come even when we weren’t braking. The car seems to be just fine, and we drove 2 hours home with virtually no problem, other than the noise.

The owner did mention the noise to us prior to the purchase, and that their mechanic said it could be related to the vacuum line (???). He never got to the bottom of it, as the car was always running fine, even with the noise.

Anyone have any information out there for me?



That squeal may be coming from a worn drive belt or possibly a worn pulley bearing, (belt tensioner, alternator, power steering pump, etc).

If you suspect a vacuum leak, you can point the nozzle of an (open) UNLIT propane torch at all air intakes and vacuum hoses (with the engine running at an idle) to search for a leak.

If the engine RPM increases at any location you have found a leak.

Thank you for the response! I’m curious, wouldn’t a vacuum leak have come up in the mechanic’s inspection as a misfire on the computer, or something? Also, do you know how serious/expensive the repairs are for a vacuum leak? Also, the noise almost has an electrical sounding quality about it that begins loud, and then fades…It is a squeal or whine sound, but not with the sound that, say, a loose fan belt would have.