Do you have an R134 kit? How will you know how much to put in if it did fit?
Sounds like you are on the high pressure side or have the wrong kit. Those cheapo Walmart kits can get you in a lot of trouble, especially if you overcharge the system. Here is a good site to learn A/C...Arizona Mobile Air Inc. (ACKits.com)
I have bought compressors, systems, etc from these people and they are very helpful.