A/C not cooling

Low pressure Schrader has definitely got a slow leak. Testing the HP Schaefer. I am going to try to pick up a tool for changing the Schrader valve stem without losing pressure in the system. Anything I should be aware of for that? At 25 PSI, has the system already been compromised and do I need to vacuum anyway? If there are other leaks they are so small that I can't see them. How beneficial (or detrimental) is the r154a with leak stop?

Thanks for the input. Had to go for a long drive today. Some of it in traffic and 80-85F in the sun. I had put a finger of a nitrile glove over the high and low p valves in case that was the problem. The A/C worked great all day! I plan to change the Schrader cores tomorrow and then pull a vacuum and then charge the system. I was under the impression that 200 PSI on the high side (45 on the low) was a target to shoot for with the compressor running and the car idling. Did I read that correctly?

Yes. Came out this morning and the glove was sucked down on the LP Schrader. Pressures were 20 and 25 so I imagine that I have a leak somewhere close as well. Changed the Schrader cores and the o-rings on the fittings on the firewall. (I was able to see a little better with the UV light as I started while it was still dark). It seemed like a possibility that they were leaking a little. Pulling a vacuum now and will recharge and let you know what I find. If this doesn't work, I think I will need a sniffer. Thanks for hanging in there with me!

Agreed. I don't have the car today, but am going to check the pressures when it gets back. I think that I will have to get ahold of a sniffer.

Well, that was not successful. The car was driven for one hour this morning. A/C worked okay. Coming back in the evening, A/C not working. I tested the A/C when the car got back. Engine still warm and idling testing 85LP and 85HP, 10LP and 100HP when I turn on the A/C. Clearly still losing refrigerant. I will see if I can get a sniffer and go from there. Thanks for your patient help.

Hey Steve. Finally got some more time to work on this. Took the car to a mechanic and paid him to use his refrigerant sniffer to try to find the leak, but no joy. He suggested that I replace the out line from the compressor to the condenser as he often sees them go. Once that was replaced, A/C is nice and cold, but still has periods, while driving when A/C basically quits. I cannot hear the click but I am thinking the compressor must kick off. Layer on the same drive, the A/C will work again. I have been waiting to see if I still have a leak, but the pressure seems to be holding.
Do you think I might have a sensor issue?

It is humid. Not musty.
Thanks for your help!

Right. Can I bypass that sensor to test if it is the problem?

I can check to see if the evaporator is actually freezing?

Thanks for the info. I will not have access for a few days, but will get back to you.

Good to know! Thanks again. Will let you know what I find.

Hello again,

Steve, I gained access to the car again. Couldn't read the resistance charts when I magnified them, so I bypassed the thermistor.
A/C seems to work fine with thermistor bypass. So I guess I will just replace that. Do you have a good source and if we run the A/C without the thermistor to control, is intermittent use okay?

Thanks again.