The kid's air conditioning hadn't been working very well. So I decided to add some Freon.


Initial air outlet temp (with system on Recirculate) was ~60F on an 85F day. After adding one 12 oz. can of R134, the temp came down to ~50F.


But then all of a sudden, the compressor started engaging with a CLUNK and cycling on and off. The A/C REALLY loads the system down now, RPM drops to 500...sounds labored.




PS: The OEM compressor had been professionally replaced with an aftermarket unit, in August 2016.





What have I done????

 

When it bogs, what's the high side pressure doing?


It's extremely easy to overcharge these small capacity AC systems. That's why a pro charges by weight.

 

My gauge set was on loan. Yeah, **TSK TSK** I know.






Still, I've charged plenty of systems just by monitoring outlet temps. And 50F. isn't that low in my experience.


Got a call out to the guy who borrowed my gauges.




+++++++++


You think I've just overcharged it? It was a really sudden issue!

 

maybe overfilled. u can purge using the can's tube. just dont plug the tube in and watch your hands from freezing

 

Have you use a can with R134a only or R134a +oil for the charging?
Most likely overcharged system. A manifold with hoses longer than 3 feet will pump an extra 2 oz of refrigerant and possible air.

 

Yes, I think it is overcharged (car not here presently). I used 'plain vanilla' R134 (no oil).


Will have my manifold gauges back tonight.



I was just so surprised about the laboring symptom, and that started SO suddenly. The outlet temp never got really cold. Most cars, outlet temp comes down into the 40sF but this happened at about 50F. My reason for posting was, could I have created an issue with the compressor?

 

Not really. According to the service manual, Fit uses compressor with no pistons so damage to compressor is highly unlikely. Nowadays cars are much more delicate than 30 years ago; I experimented with R12 substitutes in my 87 Camry, then run bare R134a on empty system, before finally scoring some R12 and charging it after condenser change and complete system flash. The compressor survived, but clutch plate got scored (I replaced it on the car). The repair lasted 4 years and was still working when I retired the car

 

Hehe. I have done the same .. used a can with a "gauge" on it, didn't realize the gauge only updates when you RELEASE the trigger! Whoops. Car blew air so cold that steam would appear in front of the vents when the compressor kicked on. You could freeze Han Solo in front of my vents, briefly, until the extra pressure leaked out over time.

My car needs a charge usually every year, slow leak somewhere. Not yet worth investigating in depth. Although this summer, doesn't seem to yet.

I think you should just let some out and see if things get better ... good news is, just by adding or removing refrigerant, you aren't likely to damage anything. If you can't figure it out, an AC pro can help and there's no harm done ahead of that. It's not impossible your high temps were due to something else and the fact that you filled it is not relevant. But overfilling is simplest explanation

 

OK, today we threw the manifold set on it...yes it had been horribly overcharged. Well, not horribly, but that's what I get for proceeding without all my 'toys'.


So after releasing excess pressure the system is working well...45F. at the vents, no loading. I was afraid I broke something. <FACEPALM>