My ac works but it does not get very cold for sure not the temperature described in the fsm. The system ahs refrigerant but probably plenty of moisture also. Do I need to empty the system and vacuum it before I properly put in new r134?
and if i do if I am not changing any components do I need to add oil after I evaporate the system?

 

You would have to vacuum the system and recycle the R134. You would be better off taking it to a shop if you are going to the vacuum the system. By the time your done buying the manifold set and vacuum you could have a shop do it for about the same price.

You should clean your condenser fins with degreaser to remove bugs and dirt that are built up blocking the air flow. Also remove rocks that are inbetween the fins. After doing this you will improve the ac temp.

 

Have a shop do it. I wouldn't mess with that.

 

Take it to a shop. They will go through your AC system and find the problem.

 

if you want to learn how to service AC system, it's not bad idea to try to do it yourself.
harbor freight sells a really cheap pneumatic operated vacuum pump if you already have an air compressor. also, you can get the manifold gauge from them as well. after you're done, you have a tool(s) that you can keep to service your next vehicle. i would consider replacing all the o-rings while you're at it too. anyways, it depends whether you are a tinkerer or not. if not, then just take it to a shop and have them do the work for you.

 

I am a tinkerer I should replace the o-rings by all the pipe connections? The shops dont do that. Also what is the story with the oil? Do I have to replace it if I am not changing any parts?

 

You don't have to change the o-rings unless the system is leaking or if you are changing out a part. You need some oil in the system if you evac it, but most freon kits will come with oil already in it.