Schrader Valve and Leak and 410a/Evaporator question

Old 06-02-20, 08:03 AM
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Schrader Valve and Leak and 410a/Evaporator question

Hi Folks,

I am trying to determine the most cost efficient method of tackling a couple AC problems. I have had problems with AC not cooling enough. Last year under home warranty I had them come out and they put in a new compressor and condenser. I wasn't exactly thrilled with the company that troubleshot the problem since they had to come out multiple times but that is another story..) This was last August and they found a leak supposedly corrected it after injecting dye into it and coming back to check for leaks. Ran fine rest of summer. Fast forward to this spring and same problem ( not cold enough) so I suspected a leak.

Had a company Precision AC come out and check and the pressure is at like 6 lbs instead of 150 lbs so guy goes definately a leak. Checked the evaporator and it looked fine but he said it was an old evaporator with a max 300 lbs pressure and with the new compressor they added 410a which could be a problem and they should have swapped out the evaporator last year to address that potential issue.

So here is the report from yesterday:

I hooked my gauges up to the system and found that it is almost completely empty of refrigerant.
I looked around and noticed Uv dye was added to the system so I did a quick check and found some of the UV dye around the fittings at the condenser. I checked under the service valve caps and found the liquid side blowing bubbles from what looked like leak testing bubbles? and or refrigerant. I checked inside the home and found that a new 410A condenser was hooked up to an old existing R22 coil which is not rated to handle the pressures of a 410A system. To fix the leaks I would recommend replacing the liquid service valve and also removing the fittings close to the condenser on the vapor side and rebrazing new ones on. Also with the pressures running through that old evaporator coil it could easily blow out any of the joints due to the age
alone. Any questions feel free to reach out.

So three questions folks since I didn't renew the horrid home warranty based on service this year)

1.Okay so there appeared to be a leak at the schrader valve hence the bubbles. He said there are products you can use to seal this ? Like a sealant? I can't recall the name he mentioned.. I would like to do this myself and test it so can you provide a best method?

2. The line you see with green on it ( that he mentioned to cut and rebraze). He couldn't confirm that that area was actually leaking or was residual from the schrader valve leaking on to it etc. I said I don't want to do that unless it is confirmed the line itself is leaking. How can I check that myself? I think he should have been able to check that but since this was the initial service call was thinking "well that's gonna cost ya!"

3. Is the 300 lbs. max evaporator coil something I need to address right away or can it wait? My understanding is R22 is being phased out and hence why the new condenser uses 410a.but does this mean everyone out there who puts a new condenser in on an older system has to swap out everything (evaporator coil) to conform?

Ideal scenario I think is seal the schrader valve and recharge the system (if line with green on it is not leaking)...He said the schrader valve alone could take it down that much if it was leaking (from 150 lbs to 6 lbs over 8 months) using the analogy of a leaking bicycle tire...

Can you provide insight please? I appreciate your time! (pic attached)


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Last edited by PJmax; 06-02-20 at 09:46 AM. Reason: removed company name
Old 06-02-20, 08:21 AM
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Don't take it bad but the mods will probably shut this thread down because of the sites TOS. I will say this, everything I've read says it's penny wise and pound foolish to mix components designed for different refrigerant type. Good luck.
Old 06-02-20, 08:47 AM
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Home warranty services are notorious for poor, incorrectly done or even dangerous work. Many times the “tech” your getting is hired based on how little they will work for, instead of skill or ability.
It’s possible to make mismatched equipment work. But it takes some skill and knowledge.
Your older coil probably has thicker copper then a newer coil would, so I wouldn’t be specifically worried about pressure. It’s more equipment capacities and getting everything to function together correctly.
Old 06-02-20, 09:03 AM
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Thanks for responding. Appreciate it. Why would the thread be shut down again? Any thoughts on the schrader valve leak and adjacent line with "green" residue on it? I could do it myself if it isn't a hassle and get a company to just recharge it. The company that came yesterday was certainly better than the "under warranty" crack squad from last year but I need to minimize costs on this so...


Old 06-02-20, 09:53 AM
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Any refrigerant handling needs to be done by an EPA certified technician. Since we have have no way of knowing who is licensed... the administrators have requested that there be no threads allowed discussing refrigerant or charging.

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