Visible leak on A/C compressor w/pic. Possible fixes?

First let me thanks EVERYONE ON THIS FORUM. I have successfully diagnosed and fixed numerous issues I've had with my 2001 Warner Bros Venture, saving me untold wads of $$$ while turning me into a do it yourselfer.

Ok, so my A/C blows hot and I've gone through all the checks I've found in these forums. Initially I thought the compressor clutch was the problem, but fixed that by changing out the relay.

Next I decided to add 1 can of r134a to find any leaks. While filling I was able to see a vapor stream coming out from the top of a brass fitting on the compressor. I shut off the engine and confirmed that it still leaked out from the fitting.

My question is this....what caused this and can I easily fix this or do I need a new compressor. The fitting looks to have a hex opening, can i tighten it or seal it?

I included a pic for reference. Thanks for any help.

No, the fitting is a high pressure valve. Designed to open like that if the system pressure is too high. R-134a is very quantiity sensitive. Being 3 or 4 ounces low or high can decrease the cooling efficiency drasticly. If your system is overcharged it willnot blow cold air. I would suggest having the system evacuated and then recharged with the use of an electronic scale ( or a ac machine) . That is the only way to be sure that it gets a proper charge for peak cooling.

I was leaning towards it being a high pressure valve. The compressor diagram I found online for the V5 had everything labeled but that. The A/C has been inoperable since last summer. There was no pressure when I connected the gauges to it.

I have read in other post about the need for having a vacuum pulled and then recharged to get any air/moisture out. I'll give that a try.

thanks