A/C Schraeder Valve Bubbling?

[YW84U]

My 91 has had intermittent A/C for the past while now. Read lots of posts on it, but its a bit beyond my scope. The compressor cycles almost every 5 seconds on/off for the most part, and often just blows lukewarm air.
I was under the hood this morning diagnosing something else, and for the heck of it, removed the black plastic cap of the schraeder valve near the rad in the front. I noticed that there is a black wet film inside, and could see small air bubbles coming out of the stem. I would assume that this is not good, but could anyone please tell me if that may indeed be the cause of the symptoms I've been having? I understand that if the pressures are off, the pump will cycle intermittently - and I figure maybe this 'leak' may be repaired and bring me back my A/C! I had the pressure switch replaced in 2000, but it only seemed to fix it for a few days, and the mechanic said that the pressures were fine at that time.

Any help in this regard is greatly appreciated!

 

[Glacier991]

This is a common leak. These valves are easily replaced. I'd suggest having the schraders replaced and having the system recharged. When they do this have them check for leaks using an electronic sniffer. You should be good to go barring other leaks.

Happy Exploring

Chris