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Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 5:03 pm
by jtupper
tbirdtbird wrote: ↑Sun May 22, 2022 4:45 pm
Yes, sounds about right, good job.
Be careful when you switch your yellow hose from vac to charge that you do not introduce any air!!
Be sure you bleed all your hoses of air.
You are probably using cans even tho that is not the preferred way.
For the first can, turn it upside down and thus rapidly charge liquid into the high side (COMP OFF)with the blue side valved off. This gets a lot of refrigerant in right away so that the comp doesn't start up with a measly charge, because such a charge will carry very little oil, and that is not good for the comp. Then you shut the red side handwheel, and charge the rest of the way with vapor (can upside right) into the blue side with engine running, comp on.
Once you are done charging be sure you have both handwheels closed in order to take pressures. With the comp running, you never want the high side handwheel open.
Once all charging is done, shut the quick coupler to the high side on the car. You now have a red hose with high pressure liquid trapped, and a blue hose with vapor. Now open the red handwheel and allow the high pressure liquid left in the red hose to bleed back into the car. Then you can shut the blue coupler, and remove the hoses entirely.
Read this over several times to get your head around it.
When charging vapor you will likely need to have a warm water bath handy because the can will get very cold and as such will not deliver the full can contents.
Report back with ambient, center vent temp at 1500 RPM, doors open,recirc on, max fan, mac cool, and high and low pressures.
The thread is long and I don't recall if 134 amounts and oil amounts have been discussed.
Also, waaay better to charge when ambient is at least 80. You will get better representation of what is going on. I would NOT charge at less than 80°
Thanks for the detailed instructions. Quick question regarding charging the high side. Should I just leave it it upside down until the can is gone or will the pressures equalize at some point not allowing any more liquid in? Also, letting the hoses drain back into the system...car running and compressor on?
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 5:40 pm
by tbirdtbird
Quick question regarding charging the high side. Should I just leave it it upside down until the can is gone.
YES
Also, letting the hoses drain back into the system...car running and compressor on?
YES but only the high side will bleed back. The low side will be full of vapor only and will not return to the car. Not to worry, there isn't much in there. It will just go poof quickly when you later unscrew the knurl.
BE SURE THE HIGH SIDE QUICK COUPLER IS CLOSED FOR THIS. BE SURE THE YELLOW HOSE IS BLOCKED BY SOMETHING. If there is a can still attached to the yellow hose, leave it, that way you don't have to bleed it. ALSO, THERE ARE USUALLY DUMMY FITTINGS on a manifold on the back where you can park the yellow hose. But you would want to bleed that hose of air at that point before opening the blue handwheel
You want the path of the refrigerant to be:
red quick coupler closed for sure
red hose liquid goes up to manifold
red handwheel open to allow liquid to cross over past the yellow hose port to the blue handwheel
then down blue hose to the open blue quick coupler
and thus return to system because of its own pressure.
The purpose here is
1. to reduce waste of 134
2. to prevent you from freezing your finger tips off when unscrewing the red hose knurl
3. Most importantly, to prevent high pressure 134 from spraying into your eyes causing blindness. Strongly suggest you wear goggles or some type of eye protection.
You are simply bleeding the hi side hose back into the system.
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 7:07 pm
by jtupper
Okay, system charged. The ambient temp when I started was about 81°, but has now dropped to about 78°-79°. I added maybe a little over 1.5 cans of refrigerant using provided directions in this thread. Best reading at center vent @1500 RPM was 41°/42°. Pressures don't seem right. Pressures as follows:
Low - 30
High - 146
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 9:17 pm
by tbirdtbird
Pressures don't seem right? Why not? I could not have done any better.
What did you determine about the proper 134 charge quantity and oil quantity?
Thread is so long, don't remember everything you did to the system
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 9:25 pm
by jtupper
Well, shows what know...or don’t know. I thought those pressures were supposed to be higher.
The compressor came with the oil pre-filled from the manufacturer. The system calls for 18oz. of refrigerant according to what JohnHere posted. I may have slightly misjudged how much I put in. I’m probably closer to 1.75 cans of 134. Should I be concerned?
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 9:27 pm
by tbirdtbird
OK, I went back. The leak was presumably at the discharge line
You wrote this on page 2:
"looks like I need a compressor, condenser, drier and o-rings. I'm also replacing the discharge line "
JohnHere posted the 134 and oil amounts on page 1. Since you used the cans, you are probably a few ounces short for the reasons we mentioned.
I did not see a discussion of the proper way to deal with the comp oil,
can you describe what you did?
Never mind we were posting at the same time.
If you used 1.75 cans you are OK because you never get all the 134 out anyway.
The preferred way to handle oil is to dump out the shipping oil from the comp, (measure how much you get out) and flush with the correct oil, then install the correct amount of the correct oil, and rotate the comp a dozen times. You do not actually know what oil came with the comp.
However it is too late now. If you really replaced all the parts mentioned above, including the condenser and drier, you should be OK
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 9:30 pm
by jtupper
I didn’t do anything with oil. The compressor came with the proper amount of oil already in it.
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 9:37 pm
by tbirdtbird
You got a little ahead of yourself, but I think you will be OK.
If you are gonna do much of any AC work, you may want to step back thru the archives for a bunch of pages and follow along with the different problems discussed. You will learn quite a lot. We don't know what is inside that comp unless we do it ourselves. Oil is discussed at length.
That high side will go up when you hit 90 ambient and higher
Re: 2008 Altima Not Cooling
Posted: Sun May 22, 2022 10:01 pm
by tbirdtbird
Why did you replace the comp? Did the previous one fail? This is important.
Drive the car on a hot day and report back
Re: 2008 Altima Not Cooling
Posted: Mon May 23, 2022 8:49 am
by jtupper
tbirdtbird wrote: ↑Sun May 22, 2022 10:01 pm
Why did you replace the comp? Did the previous one fail? This is important.
Drive the car on a hot day and report back
It didn't crater, but there were large amounts of oil and dye all over the bottom of the compressor. I could add refrigerant and it would cool, but not long. I posted the pressures and JohnHere said the compressor was failing.
It's not supposed to get above 90° until Friday. It froze me out this morning.