having dificulty w/ a/c

[MarketPlayer]

It has done this since i bought the car, and have figured out were it is comming from.  It is from I am guessing is the a/c pump, that is located right next t the engine on the divers side, petty low in the engine bay!  It is sort of cylindrical w/ thin 1/2" metal tubing going into it!  u kow when you have the a/c on, and the engine starts to rev a little bit higher, then whenit as done enough work it will slow back down?  Well everytime it does that the hissing sound starts up, and sounds pretty close to a pissed off rattle snake!  What do you think I should do?  I am going to the junk yard on friday so what part should i ask for?  thanks in advance,
-zac

[240sxspeedracer1]

my car does the same thing. &nbsp;I think it might be normal?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>
I dont know, but when the car goes to rev up, I hear a hsssssssssss, but then the hsss goes away. &nbsp;It just might be normal bro

[MarketPlayer]

I hope not, b/c whenever i cruise through a parking lot and it is doing it I get all these looks, like..."what a piece of shit...That sounds like asshole" so lets hope there is something I can do to fix it. &nbsp;At first I thought it was the metal fan attached to the radiator on the passenger side, but when i tried to find the noise it was on the oposite side of the engine bay! &nbsp;Check and see if yours is comming from the same cylindrical looking device. &nbsp;It is about three inches diameter and 5-7" long located on the lower driverside portion of the engine bay!