what‘s wrong with my AC

[clemenshess97]

Hi,

I‘ve got the following problem: I replaced most of my AC components after most of them were starting to leak.
I replaced the compressor, condenser, evaporator and drier. I refilled my system and all was good. I also made sure I got the correct parts (w/ rear AC, etc.). I didn‘t change my orifice tube, because I replaced that last year when filling my already leaking system.
Now I have this situation:
Engine on, compressor on and I get 30psi on the low side and 125psi on the high side.
Engine on, compressor off and I get 68psi on the low side and 60psi on the high side.
Could it be possible that the orifice tube is clogger after changing all the AC components or could I have used too much compressor oil? It seems like the compressor is not able to pull the gas through the orifice tube as if it is clogged…
Right now the AC is blowing hot air.
Any help is appreciated!

PS: I never evacuated real R134a into the air, it‘s always just been the cheap DIY substitute gas that isn‘t harmful.


It‘s a 01/2003 Tahoe, 5.3L LM7

 

[swathdiver]

How did you calculate the amount of refrigerant and oil needed and introduced? Did you take into account that some components came with or were without or still had oil in them?

Did you use a manifold or just cans with the little gauge?

 

[noodlesandsam2]

With Rear A/C - 2.7 lbs ( 43 oz ). The XL just took 3.0 lbs ( 48 oz ). I know it has a slow leak, but I needed to get it filled to get a baseline. It's very nice to have it working

 

[RST Dana]

Wait, after you patched it back together, did you forget to mention you vacuum tested the system? If not, you missed as step!

 

[OR VietVet]

You did not replace the orifice? WHAT!

The engine on and compressor on high side temp seems low, like you are low on refrigerant. What is the ambient temp?

The pressures should equalize when compressor shuts off.

It has been years since a/c work because the a/c stuff is not big business here in Willamette Valley, Oregon.

 

[clemenshess97]

How did you calculate the amount of refrigerant and oil needed and introduced? Did you take into account that some components came with or were without or still had oil in them?

Did you use a manifold or just cans with the little gauge?

The compressor came prefilled but it wasn't enough for the entire system according to the guide I found, so I filled the rest with the correct PAG oil. I also weighed the cans during the filling process to make sure I don't overfill the system. I used a manifold and not the small gauge hose that comes with the cans.

 

[clemenshess97]

Wait, after you patched it back together, did you forget to mention you vacuum tested the system? If not, you missed as step!

Forgot to mention it.
I did pull a vacuum for 30mins and then waited another 30-40mins to see if it holds vacuum, which it did.

 

[clemenshess97]

You did not replace the orifice? WHAT!

The engine on and compressor on high side temp seems low, like you are low on refrigerant. What is the ambient temp?

The pressures should equalize when compressor shuts off.

It has been years since a/c work because the a/c stuff is not big business here in Willamette Valley, Oregon.

I didn't...thought I wouldn't need to because I replaced it not so long ago...I should have double checked that.
Ambient temp was 77F during the pressure test.
The refrigerant came with a dye and I already checked for leaks with a UV lamp...couldn't find any leak.

 

[swathdiver]

The compressor came prefilled but it wasn't enough for the entire system according to the guide I found, so I filled the rest with the correct PAG oil. I also weighed the cans during the filling process to make sure I don't overfill the system. I used a manifold and not the small gauge hose that comes with the cans.

There was already PAG oil spread throughout the system. Did the new condenser come with it? Did you account for this before adding more?

Sounds like you did everything just as I have done.

 

[clemenshess97]

There was already PAG oil spread throughout the system. Did the new condenser come with it? Did you account for this before adding more?

Sounds like you did everything just as I have done.

Only the compressor came pre-filled.

 

[swathdiver]

Only the compressor came pre-filled.

I forget, do you have a scan tool or code reader that can read any internal BCM codes?

We have some AC guys on here, @Scottydoggs my memory hasn't been too good lately.

 

[clemenshess97]

I forget, do you have a scan tool or code reader that can read any internal BCM codes?

We have some AC guys on here, @Scottydoggs my memory hasn't been too good lately.

I don't...just one of those cheap scanners for the ECU.

 

[swathdiver]

I don't...just one of those cheap scanners for the ECU.

IPhones with the CarScanner app from the Apple Store can read BCM codes with a basic OBDII adapter.

 

[Summajet]

Hi,

I‘ve got the following problem: I replaced most of my AC components after most of them were starting to leak.
I replaced the compressor, condenser, evaporator and drier. I refilled my system and all was good. I also made sure I got the correct parts (w/ rear AC, etc.). I didn‘t change my orifice tube, because I replaced that last year when filling my already leaking system.
Now I have this situation:
Engine on, compressor on and I get 30psi on the low side and 125psi on the high side.
Engine on, compressor off and I get 68psi on the low side and 60psi on the high side.
Could it be possible that the orifice tube is clogger after changing all the AC components or could I have used too much compressor oil? It seems like the compressor is not able to pull the gas through the orifice tube as if it is clogged…
Right now the AC is blowing hot air.
Any help is appreciated!

PS: I never evacuated real R134a into the air, it‘s always just been the cheap DIY substitute gas that isn‘t harmful.


It‘s a 01/2003 Tahoe, 5.3L LM

I forget, do you have a scan tool or code reader that can read any internal BCM codes?

We have some AC guys on here, @Scottydoggs my memory hasn't been too good lately.

Did
the compressor fail and is the reason for all new parts? Did you flush the evaporator with a flush?

I would place a high volume fan in front of the condenser and watch the gauge and also temp reader. I had an issue and it was the thermal fan clutch on my 03 yukon. Low and pressure was good but the high pressure was over the range it should have been at.

 

[RET423]

No A/C system will make cold air with only 125 psi on the high side & 30 psi on the low side is very near the low pressure cutoff point in the pressure switch

You have too much oil if brought it to the spec without doing a full system flush, vacuuming doesn't get all the oil out; just whatever flows in the freon.

So you likely have a restricted orifice tube (pressure won't equalize), too much oil (degrades performance of the freon) & a moisture saturated dryer (due to trapped moisture in the oil you didn't flush out)

 

[catfishcrook]

You did not replace the orifice? WHAT!

The engine on and compressor on high side temp seems low, like you are low on refrigerant. What is the ambient temp?

The pressures should equalize when compressor shuts off.

It has been years since a/c work because the a/c stuff is not big business here in Willamette Valley, Oregon.

2003 tahoe, willamette valley. I have been working on my wifes ac , with no success. Shop wants 240.00 to look at.
So to start with, the clutch made grinding noise, afterwards ac stopped.
I replaced clutch, started working, then stopped, so thinking it was the compressor, I replaced it, and so vacuumed system, then attempted recharging, all seemed good, but clutch didn't kick on. After checking with internet, one said to check with the compressor relay ie. 87/ 30 to jump compressor. Too much information I know, after attempting to jump relay, clutch clicks. But does not continue, so after reading I assumed it didn't have enough freon, after which I had just installed 1.75 pds. System asks for 3 pds, this is a dual ac system.

Glad I have not had any of these problems with my 94 f150 I've had for 30 yrs an no problem with AC

I appreciate any help, seems it's quite involved with office tube, tearing up interior etc

 

[OR VietVet]

2003 tahoe, willamette valley. I have been working on my wifes ac , with no success. Shop wants 240.00 to look at.
So to start with, the clutch made grinding noise, afterwards ac stopped.
I replaced clutch, started working, then stopped, so thinking it was the compressor, I replaced it, and so vacuumed system, then attempted recharging, all seemed good, but clutch didn't kick on. After checking with internet, one said to check with the compressor relay ie. 87/ 30 to jump compressor. Too much information I know, after attempting to jump relay, clutch clicks. But does not continue, so after reading I assumed it didn't have enough freon, after which I had just installed 1.75 pds. System asks for 3 pds, this is a dual ac system.

Glad I have not had any of these problems with my 94 f150 I've had for 30 yrs an no problem with AC

I appreciate any help, seems it's quite involved with office tube, tearing up interior etc

You have done this repair one step at a time and should have replaced the accumulator and low pressure cycling switch at the accumulator. You also should have replaced the orifice. Should also have flushed the system while opened up. When you pulled a vacuum, how many inches did it pull and did you shut off for 10-15 minutes and see if it has a leak in the system? Especially since you have had so many starts and stops, replace that relay, too.

Or, run around with the windows open all the time in the beautiful Willamette Valley, where I live, too. I hardly ever have the a/c on because the weather is nice and very low humidity.

Where are you in the Valley?

You also should have started your own thread and you will get a lot more responses.