where are the common leaks on a blazer a/c? I charge it and it only lasts a week.

 

Probably the most common area is belly leaks in the compressor body itself.

 

Look on the metal lines near the MAF sensor. Mine rubbed thru and had a small leak there. They also like to leak where they connect at the compressor and at the connections where the hoses hook up to charge it up.

 

+1, anywhere ther is an oring there is a possibility for a leak. You can get a can of r134 with dye in it so you can find the leak or look for any oil/ wet spots on the ac system and that's where the leak is.

 

Most people never think to look at the schrader valves. Its common that they leak and thats why the caps have o-rings also. I know its a simple thing when you think about it but like I said, most dont think of it, and its fixed leaks for me in the past. Checking for oil is a good way to spot a leak but you would not think anything of it if you seen some oil on the SV. Could it be from filling? Most would think so. Not always the case though. So if its empty change them out and put some new caps on. Could be a cheap easy fix but check for oil in other places also. Pressure relief valve needs to be looked at also to see if its shooting your coolant out.

Also cheap easy and performance fixes would be to change the Dryer and orifice while your at it.