AC & pressure equalization time

[TahirTu]

Hello all,

I'm curious to know how much time it should take for the refrigerant pressure to equalize after shutdown to call it safe and not suspect issues with the orifice tube?
In my case its almost like instant 2 seconds or so.

For those who have knowledge about this point your help is appreciated.

 

[JeepJeepster]

You would be able to tell if something was wrong with the orifice by putting some gauges on it.

 

[TahirTu]

Of course, btw i read your post a minute ago seems you have done a good job congrats for that.
If by any chance you haven't had your system recharged yet, Can I ask a small favor? after completing your recharge and with the gauges still hooked up shut the off the AC and just monitor how much time it takes for the pressure to equalize on both sides. that's what i need to compare. thanks in advance

 

[JeepJeepster]

Sure will! Ill take a video for you and try to upload it to youtube. Should be able to do it tomorrow.

shes still holding vacuum btw. It had dropped down from ~30 to 27 so I let the pump run again yesterday evening. Checked it at lunch today and it was still at ~30. With all of the ac systems Ive worked on, I shouldve gotten a bottle of nitrogen and a 30lb jug of 134a. The proper way to check for a leak is not buy pulling a vacuum... and Im may or may not have used shop air before....

 

[JeepJeepster]

Here you go

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Clutch kicks off at 13 and I would say they are equalized at 50sec.

 

[TahirTu]

Yes! Thank you so much I think I can see my problem now, in my case the moment the Compressor kicks off it all equalizes too quickly much much faster then yours in the video, I'm suspecting if i replaced the line with the orifice tube that could be it's fix, what do you think?
I started to question my AC when i noticed it started to blow less cool air while idling, also noticed the clutch doesn't cycle at idle like i remember it used to do, got me suspicious and hooked the gauges, I found pressures at idle are (55psi low / 210psi high) at 2000rpm (reaches 20psi kicks off/ max. 260psi high) I couldn't really find anything i should do as it is cooling fine when driving. I should mention the weather where i live easily get 100 - 110 F
One night i realized that i had repeatedly saw that right after i shut it off to unhook the gauges pressures drop to be equal rather quick (in fact too quick that there's is not enough restriction that in return affects the AC performance at idle), and then i questioned "how fast/slow that normally should be?"

I could be wrong with my assumptions though

 

[JeepJeepster]

Im by all means not an A/C expert, I just understand the basics. With the pressures being normal I do not believe the orifice would be bad. If you had a normal low pressure and a low high pressure then I would suspect either the compressor or the orifice. Im not sure the orifice can fail in such a manner though. If you had normal low pressure and really high pressure on the high side then I would think the orifice was clogged.

There should be a check valve somewhere and Im assuming its in the compressor. This keeps the pressure from back feeding once the compressor kicks off.

 

[adamkrz]

I would definitely change the orifice tube before anything else since it seems your compressor is working.

 

[TahirTu]

I'm going to replace both the Compressor and AC line, If i don't forget I'll post my results, thank you for your help