Car A/C Drains out to Compressor Switch Minimum

[pha3z]

I'm really confused.

I thought I had a bad a/c pump on my car, so I replaced it. I had a local shop with a nice a/c machine charge it to 1.14 lbs. Its a Toyota Corolla and the spec calls for 1.14 lbs max and 1.01 lbs min. I got back on the road and within 10 minutes, it lost charge and stopped working. I went back two days later and they told me there was 0.98 lbs in it. The new guy claimed that the old guy probably didn't charge it right. I was skeptical but I let him charge it up again to 1.14. I got on the road again and within 10 minutes it loses charge and stops again!! I go back again and they drain it and the machine says it reclaimed 0.98 lbs again!!!

So in a nutshell the behavior is this:
Charge the system to max.
Run the a/c for 10 minutes and it loses charge.
Check the coolant and find that its just barely below the minimum threshold for the pressure switch to come on.

So why would the coolant be leaking with the pump on but then stop leaking when the system kicks off?

Am I crazy or has anyone else seen this behavior?

 

[nehog]

...

So why would the coolant be leaking with the pump on but then stop leaking when the system kicks off?...

Bad seals in the compressor would do this. A small leak in the high pressure side would leak much more when running, then if off.

I'd try a different A/C shop if you can. They need to find the leak, either with dye, or a sniffer.

 

[Josh B]

Go to your parts store and pick up a can of R134a with the UV dye in it. Try to get one with a reusable gauges if possible. If you don't have a UV light or flash light, I suggest you pick one of those up too.

Turn your car on, crank on full cool air and max ac, make sure you hear the clutch engage on the compressor. If you are low on refrigerant you may have to jump a pressure switch to get the compressor to kick on. Remove the low side port cap, shake the can, and attach the hose + can to the the port. Discharge can while rotating in a circular motion. Once the can is empty, remove from port, put the cap back on.

Wait five minutes or so, then start looking for leaks with your light. I start at the firewall then follow the lines to the front. Make sure you get a good look at all your fittings, compressor, and condenser.

***NOTE: I am no expert or qualified technician, but I just fixed my Honda's A/C leak when I found a crack in my condenser. I ended up spending a total of maybe $200.***

 

[Milton Shaw]

Check your pressure switch it could have a leak when its got enough pressure and when the disk inside snaps back to low pressure its stops leaking. You have a leak somewhere for sure that only leaking when its fully charged. I have seen some of the switches on compressors do some funny things over the years, leaks and intermitant connections are common.

 

[bigdav160]

I had a local shop with a nice a/c machine charge it to 1.14 lbs.

I went back two days later and they told me there was 0.98 lbs in it.

Your system is not leaking. The charge is "not lost"

Something else is wrong.

 

[chrommagman]

it seems like you have a leak in your system. like Josh B said use the die and check for leaks.

I have one question, are you having to pay each time they fill your system? if so that is NOT cheap!!!

but it sounds like it could be your compressor!

 

[blacK20]

How do you know that the cause of the ac not working is due to a refrigerant leak? Especially when it was recovered twice and almost a pound came out of it? I guess my question is... are you assuming there is a leak when there is no evidence of any?