No air conditioning after recharge

hey guys, I got my a/c recharged 1 week ago and it all seems to have leaked out. When my mechanic was re filling it was holding at vaccum and seemed fine for a few days but now im back to square one. Not sure where to start trouble shooting. What are the most common components that need to be replaced and should I buy oem replacements or aftermarket (rockauto) parts?

 

I'd start by bringing it back to the shop that did the recharge.

 

He should have put dye in your AC and tracked it down. How long was the vacuum test done? This is hard to diagnose over the Internet because it’s something you have to thoroughly go through with a fine tooth comb.

If it held vacuum for 30-60mins then I would check the fittings to make sure they’re not damaged and leaking. Realistically though like I mentioned before a dye would be my first choice, unless he has a Freon sniffer and I would go from there.

alternatively you can shotgun it and replace every o ring in the system and put in a new condenser, and if that doesn’t fix it then replace any rubber hoses if your model uses those on the ac lines and finally the evap

 

Thats the plan. I am replacing my lower control arms and wheel hub this week and i have to take it back to the shop for the alignment. Was just trying to troubleshoot myself until I have time to take it back in. Trying to figure out whats the most common problem people have come across.

 

Ill have to take it back to him and get him to retest. Im not sure exactly how long it held at vaccum but i dont think it was 30 min. I have heard of the dye before but he didnt mention it during the refill. Said something like if its holding at vaccum it should be fine. ‍♂️

 

Are you even sure the mechanic is certified or knows what he is doing ?

 

Amvicc certified and has his red seal certification document hanging over the front desk. Yeah definitely certified, in fact the only guy I trust not to fuck me over. I dont go to the dealership, last time i went there, they charged me 105$ for 8 nuts and 8 washers...

 

The mechanic doesn't do the vacuum test, The a/c machine does the leak test.

With the hoses connected the machine pulls a vacuum on the system and then sits back and waits to see if the pressure drops. The mechanic goes and does something else for a half hour until the machine beeps. If the vacuum holds and doesnt drop the machine says "leak test passed", if the vacuum drops down to a certain point the machine days "leak test failed". Ask him if the leak test passed.. I imagine it did (at the time) or he would have said something

 

You sir are correct. I was standing there beside the machine while the whole process was happening. Hes good like that, (shows me old parts he takes off ect.) the machine said it was holding vaccum and it showed I had next to no refrigerant left. worked for a few days after the recharge like I said but now it seems to be gone. Now im here to see if anyone has ideas before I take it back.

 

If the system is consistently holding vacuum, a cheap place to start would be replacing the valve cores in the service ports. They are basically just fancy Schrader valves, they get hung up and won't seal properly, and a leak there won't show up during a vacuum test because thats where the hoses are connected.

Spray some soapy water mix down into the service fittings and see if they bubble up

 

Regardless of what the vacuum test showed on the machine. The facts are:

It was working and properly charged at some point.
It lost the refrigerant and was not working.
The only way for the refrigerant charge to drop is a leak.

Recharging the system is not a fix under any conditions only a temporary bandage. Unless the leak is tracked down and repaired you will be stuck in a vicious cycle.

Your mechanic should have told you all of this. Leaks do not repair themselves. If you have a UV Light you can look at the connections and such in a dark area. If there is dye in the system and you shine it where the leak is it will be obvious.

Pray that it is not the evaporator that is leaking.

 

It’s a sealed system.

No refrigerant = leak. It exists somewhere, gotta find where.

 

Im going to guess as well but I have to say its the Schrader Valves. With all lines hooked up and you held a vacuum it makes it kinda a no brainier unless you replaced something else. Its a cheap and easy fix. Oreiily's in my area lets you borrow a manifold gauge set and a vacuum pump for free. So to fix it you might be out 20 dollars and a couple of hours of your time.

https://www.oreillyauto.com/detail/...e-set-not-stocked-in-all-stores/67127/4700298

https://www.youtube.com/watch?v=Pdq8JAlct6s

 

I'll add to the already useful info here... Go to Lowe's and get a craftsman uv flashlight. There's dye in the system from the factory and the UV light should highlight it. Pull the gasket of where the lines go into the fire wall. That's the expansion valve and there are O rings on it.