Shop gave up on AC system (Page 2/3)
Xenoblast OCT 26, 08:53 PM

quote
Originally posted by theogre:

If Weather is Cool or Cold, then will have problems trying to work on Car AC and many others. Like Many HVAC companies for home etc won't charge or even test AC systems when Weather is < ~ 65°F for same reason. even inside needs to be inside for hours for car to warm up > 60 -70°F minimum.




It was 85 degrees today, so I think I am good in that regard.
skywurz OCT 26, 09:47 PM
Idk in some older posts i read 25oz for 134a. When i did 32oz the system would reach high side cut off under acceleration. My cheap HF gauges were saying it was low but when i added 134a based on pressure and not weight it also cycled off at high rpm worse. I tried 25oz (because i could always add more)i never cycle off and it was freezing cold 38 degrees on a 80 degree day.
LornesGT OCT 27, 12:04 AM
If indeed you have that much refrigerant in the system then it is most likely have a restriction. When restricted bad enough the suctions drop quick as noted so that head pressure never build up. Bypass low side switch and you will probably go into a vacuum, with a full charge your low side should not unless gunk or something blocking path.. Look for frosting point and this is your restriction. Good chance at the orifice tube.
Don’t leave it running a vacuum long this is not good for the compressor as the refrigerant cools the compressor.

[This message has been edited by LornesGT (edited 10-27-2021).]

theogre OCT 27, 01:04 AM

quote
Originally posted by LornesGT:
If indeed you have that much refrigerant in the system then it is most likely have a restriction. When restricted bad enough the suctions drop quick as noted so that head pressure never build up. Bypass low side switch and you will probably go into a vacuum, with a full charge your low side should not unless gunk or something blocking path.. Look for frosting point and this is your restriction. Good chance at the orifice tube.
Don’t leave it running a vacuum long this is not good for the compressor as the refrigerant cools the compressor.

Too much Oil can do same.
Many car systems have too much oil because people keep adding 2oz every time recharge then do conversion to R134 w/ 6oz or more of new oil on top of that.

Even if replace the compressor and ACC/Dryer, the evaporator and other parts can hold a lot of oil.
Xenoblast OCT 27, 12:55 PM
[/QUOTE]
Too much Oil can do same.
Many car systems have too much oil because people keep adding 2oz every time recharge then do conversion to R134 w/ 6oz or more of new oil on top of that.

Even if replace the compressor and ACC/Dryer, the evaporator and other parts can hold a lot of oil.
[/QUOTE]

I added 8 OZ to my system before putting it back together. Is that too much? Also perhaps the shop added oil charge on top of that? I told them I added oil so I hope they didnt

Also I will go out today and rent that gauge set. Perhaps Ill bleed out some of the refrigerant to 25 OZ. Does that 2 pound number include the oil? that could make sense that way if Im overcharged.

[This message has been edited by Xenoblast (edited 10-27-2021).]

theogre OCT 27, 01:28 PM
Refer oz Does Not include the oil.

But that assumes the system have correct oil load.
In general when loading oil for a "dry" system, ½ to compressor other half to acc/drier in many cars.
but some other system are not the same. You need to know exact compressor you have when replacing because what in FSM etc might not = to the "New" compressor, contact the vendor or company make/rebuild it. Or can hydro lock the new compressor filling w/ too much oil in the intake port.

Again, even w/ replacing compressor and acc/drier the Evaporator and other areas can hold a lot of oil.
And worse the R12 oil trapped there and and other places stays there w/ R134 taking up space used by the refrigerate.
Xenoblast OCT 27, 03:25 PM
I got the gauge set. When running, the high side slowly creeps down to 100, but then when the compressor kicks on it goes up to 150. The low side slowly creeps up until 45, and then goes back down to 21. One thing I noted is that after only a couple minutes with the engine off, both sides equalize in their pressure at around 110 psi, is that normal?

Also its 85 degrees today again

[This message has been edited by Xenoblast (edited 10-27-2021).]

RWDPLZ OCT 27, 03:59 PM
85 F ambient temp with a reading of 110psi is too high. Was that right after you turned the car off, or after it's been sitting a while? If sitting at least 30 minutes, overcharged.

https://ricksfreeautorepair...ic-pressure-reading/

While the vehicle is running, 150 on the high side is too low, should be more like 230. Since we know the system isn't undercharged, this would most likely indicate a blockage at the orifice tube, or somewhere on the high sider. Evacuate the system, and check for debris or blockage at the orifice tube. The variable orifice valve may be defective, you can rule this out by swapping in a standard one, which has no moving parts.
Xenoblast OCT 27, 06:13 PM


Orifice tube came out covered in oil. Is this normal? Thinking the shop added some oil.

Should I try and take out the accumulator and see if i an get anything out, or should I leave it?
Xenoblast OCT 27, 08:18 PM
Success!


I didnt end up draining any oil, and just replaced the orifice tube with a non-variable one.

I added 36 oz of regrigerant, altho probably closer to 30-34 because I accidently took off the first one prematurely. high side guage showed 150, so I guess dont pay attention to the gauges to much.

It got cold by the second can but I just added more to see if I could get it lower, it got a little lower but not much.

[This message has been edited by Xenoblast (edited 10-27-2021).]