You have a bad leak if it's leaking down in one day. Most common leaks are the green oring on the hose connections or the shrader valve where you fill it at on the low pressure side. Look at your hose connections more closely for traces of dye. I have a meter that measures oxygen content which is great for finding leaks.
In response to "Pops"... Ok that's probably true but I think I have a leak too? I've put in 4 cans of R134a, in about 3 days. After each day the system is low and the compressor stops turning. I've used R134a with oil sealer and stop leak with dye but I can't seem to find the leak! Got any tips?
It's low on charge. Readings will vary with ambient temperature, here's a chart that will get you in the ballpark: http://www.idqusa.com/faqs.php?faq=74&faq_id=74&category_id=1
Ok so I spent a couple hours searching for a "leak" but with NO luck. Tomorrow I will fill system to the recommended 3.7 lbs of R134a and hopefully this will solve the problem!
Update: Three days after I fully charged the system it was down again. Coincidentally the temperature dropped this week here in Carlsbad from the 100's to the 80's. Yesterday morning I raised the hood to do my inspection and there it was staring me in the face... a huge leak coming from the high side hose connection to the compressor. It was leaking so bad that it was running down onto the top of alternator and turning it green! So I immediately put it in the local shop (Reliable Auto...the best service station in Carlsbad) and they evacuated the system, replaced the bad hose and got me recharged and back on the road again blowing ice-cold A/C!!! Lesson learned... and special thanks to all of your comments and advice.
Glad you got it going, nothin worse than no a/c in these furnaces!! Lol. Never mind the naysayers. The stop leak was pretty much taken care if with the evac. There may be a little left but not enough to hurt anything. Trust me, I've been through this before
Correct! The system obviously has a leak....best thing to do is put some dye in it, trace the leak, make repair and recharge....the money you'll save on Freon will pay for it.