DIY: add freon

I got a used civic last summer, the AC was working well then.  But now it is not blowing cool air.  I am thinking of adding some freon to it by myself.  

I called Autozone, they sell a set of things for 30 dollars:  a small can of freon, the gauge and hose.  They also sell things separately, like freon, hose, at different prices. 

If i buy the whole set for 30 dollars, do i need to buy another can of freon?  What are some of the tricks I need to be careful if I add the freon by myself?

Thannks a lot!

所有跟帖： 

• 回複：Make sure the system does not leak before you add Freon. -wimax88- ♂ (137 bytes) () 03/18/2011 postreply 09:42:42

• can you do that for your house AC? -行者1000- ♂ (0 bytes) () 03/18/2011 postreply 10:33:54

• 成分不通用.現代車用多R134A,家用R12.後者要執照 -滿地找牙- ♂ (0 bytes) () 03/18/2011 postreply 14:14:19

• 好像house AC灌氟要執照 -beHappyLOL- ♀ (0 bytes) () 03/18/2011 postreply 10:53:23

• 灌的時候，並住呼吸，別吸到肺裏 -bushihandyman- ♂ (0 bytes) () 03/18/2011 postreply 16:10:37