Leaky low side valve

[93TwotoneXLT]

So, I went to charge my X, and when I took off the dust cap the service port starting hissing at me. I am assuming that the valve is leaking as I can feel air/charge coming out of it. I have no A/C experience other than hooking up a can of freon so my question is this: How do I replace the valve in the low side service port? I am converting from R-12 to R-134a and I do not want to put the adapter on until I can put the new valve in so that it won't leak. Thanks for any help!

 

[shamaal]

The A/C schrader works in principle like that for a tire, however they are larger. Check the A/C section of your automotive store for a kit with a new valve and a removal tool.
To replace, the system will have to be empty. There is a $50 tool that can remove it from a pressurized system, but if you're converting to R134a the system will be open anyway.
For general knowledge about the R12 to R134a conversion, check the stickies at the top of this forum.

If there's a particular aspect you do not understand ask questions.