I need help with a noise on the car

[man_of_steel83]

alright guys,

this afternoon i heard a noise from my rear wheels, i figured it has something to do with the brakes. cause when your coming to a stop, it goes away while braking, then it comes back. Its the same sounds as to when you have a nail in your tire, then you take it out, the sounds as if air is leaking. at first i thought it was that of a air leak but im sure it something with the brakes. for the record My dash cluster stayed clean, i had no lights come on.
Later that night i drove the car again after it sitting there for 3 or 4 hours and it went away. and input as to what that car was doing would be great

[man_of_steel83]

Nobody has any ideas?

[gnomee]

Well I'm unsure why the brakes would affect it. However, I have noticed after a long drive my car has made me franticly look for a tire leak to find out it is some sort of hissing noise in back. I'm assuming its the fuel pump, not sure if is just sucking that much air in as the gas is getting pumped out or not.

Thats my take though..

[SVG210]

fuel pumps hum, if something is hissing its porably an air leak, could be your bearings.

[man_of_steel83]

the weird thing is that it did it for two days, and it hasn't done it since.