stupid s/c question

I recently had to swap my a/c compressor as the stocker was frozen. Pick n pull was having 50% so I scored a new/old one. Well, it is an aftermarket setup (seltec 13hd already setup for r134). Anyways, I swapped over correct hoses, condensor, and new drier... I know Im supposed to evaq, but my friend gave me a can of r134 and we figured.. what the heck. No leaks, clutch kicks on... no cool air. I forgot to replace expansion valve. Now I have to get it evaquated... but were is the expansion valve? Im going to order one from rockauto... Help? Anyone?

One can is not enough to make it cold.
I wouldn't worry about the expansion valve, unless you know trash went through the system.
You want to evacuate the system for sure, as any air in the system could contain moisture, which will cause an intermittent cooling problem.

ok. I am using one of those cheap gauges that screws onto the can from walmart... it says I am at 50lbs and nearing the red. Sucks... called shop to get a price to evaq... $50! That blows! Anyways, guess I will have ot figure out how to use the one at my dads shop...

Here, one can get loaner vacuum pump from AutoZone. Get real gauge set there as well, or at dad's shop, very common piece of repair equipment these days, 99% of the vehicles have AC. If your dad's shop has one use that, very important to a functioning system.

The expansion valve is under the dash, in the evaporator box, so that whole assembly needs to come out to replace it. I agree with Sin City, leave the expansion valve alone for now. Evacuate the system at least 45 minutes, then add the correct amount of R134a - no sealers or conditioners (UV dye is OK to add).

Did you add any refrigeration oil to the system? If not, before evacuation would be a good time.

I won't turn you into the feds when you release the R134a into the atmosphere that's already in the system, but that's illegal to do.

I never added any oil as I figured I did not need to since the compressor has never been drained. This set up I have someone had installed completely after market. Nothing I had previously worked. I will goto pop's shop after work and evaq system
(there is a machine there), and recharge. Thanks for the help!

Since you replaced a few components, and each of them was probably holding a little oil, you'll probably need to add back in most of the system capacity. Here are a few nuggets about oil from Sanden...

Is this the same for all COmpressors? Mine is not a Sanden. It is a SelTec.

pretty much so...

yipee!