Saturn Repair: 1996 Saturn SL2 Compressor, radiator fan, car overheats

Question
Hi Chris,
The valve on my compressor, i believe its the low pressure one, is leaking.  As of now, there's no more freon in the condenser b/c of the small leak which I heard myself.  Any ideas on how to fix it?  What type of Freon does it use?

Also, I've noticed that the car overheats a bit and once the temp gauge goes past the 1/2 way mark, the fan engages and it cools down.  However, that was never a problem before.  I recently replaced the radiator b/c it was cracked.  Also, when i turn on the AC, the radiator fan automatically engages as well, which it never did before.  Sometimes I have to turn on the AC just so it doesn't reach that half way point so it would cool down.  Any ideas?  Thanks Chris.

Answer
Rami,
 The freon that your '96 is 134-A.  You should be able to pick some up at your parts store, it's getting more expensive though.  
 Replacing the leaking part is the only way to fix an A/C system due to the high pressures.
 When you turn on the A/C, the fan should kick on.  This is a built in feature that keeps your engine from overheating due to the high temperatures running through your condenser.  I would look at the ECT sensor to make sure that it is not cracked.  That should keep your engine cool.

Chris