Some AC freon or oil or stop leak seems to leak on to the windshield. Any idea where
 

Some ac freon or oil or stop leak seems to squirt on to the windshield. Does anyone have any idea where it is coming from? Thanks in advance. :)

Inside or outside?

Outside of the windshield. I will see just little spurts of oil/freon on the glass after trying to charge it up.

You won't be seeing any refrigerant on your window, as it will instantly boil off.

You're probably just losing some from the connection and spraying it around. A "manual" coupler helps a lot there.

What I see on the winshield is a few spurts of what looks like sap from trees but only happens when I work on the AC. Maybe you are right.

When I remove my plastic cap a tiny bit of freon/oil seems pressurized and comes out. Does that mean the valve is bad?

Service valves always leak, and require caps to keep the system tight. That yours releases pressure when you remove it means that the cap seal is working.

That is good to know. Thank you. :)

The schrader valve leaks are so prevalent that I've gotten into the habit of putting an o-ring in the plastic cap just so it absolutely seals.

My caps have o-rings in them. If yours don't, unless it's missing, get a new cap that uses one; some cheap caps do not use o-rings. If there isn't a proper groove for the ring, it may not seal very well if you put the cap back on just a bit too tight.

It is easy to dislodge those o-rings when you open the cap. Always ensure that you don't lose it.

Oh, and quit putting stop-leak in your system. That stuff is trouble.

Would 2 orings in a cap be better or worse than 1?

Much worse. Worse than adding an o-ring where there is no recess to hold it in place.

That is what I figured but thought I should ask to make sure. :)

Replace the leaking valve... there is a tool to do it without removing the charge. I've got one for R-12 shrader valves -it cost me about $35.

M

Do you know the name of the tool or a link?