Guys,

I recently changed my power steering pump and since I have done this when the car is idling from inside the car I can hear what sounds like an exhaust fluffly leak coming from the rear left handside of the car. When I rev the car above about 1200rpm the noise disappears. I am wondering if I have a vacuum leak.

I can't really hear it from outside of the car as there is too much other mechanical noise going on. Any clues?