giperbolic

I tried to follow a/c vaccum and recharge DIY on here, but ran into some issues.
First, I pulled vacuum, using Autozone pump and it got it down to -28. I left if and vacuum dropped over the next few hours, so I have a leak. I figured I charge it with freon, containing dye and check it with black light. I vacuumed it again and once it was at -28 again, I connected a can of freon and started to fill it up through the low side. Unfortunately, I didn't follow DIY at that point and didn't start the car before filling it up. So I got a low side to 30 psi, then started a car. Here the issues:
1. Compressor was making gurgling noise. I did put 4 oz of oil into the suction port of compressor and after hooking the line up I spun it by hand to move the oil. What can be causing that?
2. I kept filling the system up while the car was idling. My low side pressure was around 50 psi, while high side pressure went to ~250-270psi after I was done with 1 can. Is that normal?
3. Air was getting cool, but then started to blow hot. What could have caused that?
4. Before unhooking and empty can to put the 2nd one on, I noticed that high pressure line got extremely hot, very hot to touch. This made me shut the process down and get help. What could have caused that?

Former User

I think the high pressures with addition of only 1 can of refrigerant suggest that there is air in the system.

giperbolic

I did vacuum it again prior to filling it up. As I said my vacuum drops over for 3-4 hrs, so the leak is not too big to have air while filling it up. Does compressor noise indicate mechanical problem or is it the oil that I filled it with that not distributed yet?

Former User

I thought that possibly you allowed some air in while recharging (e.g., open valve on low or high side of gauge set). Was the condenser fan running when you measured the pressures? Was it a hot day and you were in the sun? What happens to the pressures if you spray water on the condenser?

giperbolic

I'm pretty sure no air went into the system. It was a hot day, but I was working in the garage, i.e. not in the direct sun. I haven't checked if condenser fan was on, nor have I tried to spray water on it. Do you have any idea why would return line be extremely hot?

Former User

When the compressor pressurizes the refrigerant, a lot of heat is released. This hot refrigerant is cooled as it passes through the condenser. So it is normal for the high pressure side to become very hot.

srmofo

you said the high side line was hot??? then you said the return line was hot??? Which is it? If the high side is hot and the pressures are high then there is a chance you have a restriction in the line.

Air in the lines will not cause high pressures. you remove air so there is no moisture in the system

Why did you need a recharge?
did you replace a compressor?

Remove the orifice tube and check it for metal shavings.

the air was blowing cool the got hot because the compressor was shut off by the high pressure switch.

Check to make sure the condenser fan is coming on.

Former User

Based on the OP's low and high side pressures, the high side line was most likely hot as was stated in the first post. In addition, the low and high side pressures don't seem imbalanced, suggesting that there is no restriction.

This statement is incorrect.

giperbolic

The line that was getting hot is the High pressure. I mistakenly called it return, meaning, return from the compressor (discharge).

I'm in the process of installing A/C in the car that had all the components stripped. I got all the components, throughoutly cleaned every line, using flex brush, ac flush liquid and compressed air, cleaned evaporator and condenser. I bought a used compressor, ran some oil through it while it was off the car - it came out very clean, drained oil completely (as much as I could) before installing, then added 4 oz to the suction port once installed. I did buy new expansion valve and drier, but I wanted to see if the system has any leaks, so for this leak troubleshooting I'm using old ones.

I know that high pressure line should get hot, but didn't expect it to be "burning hand" hot.
I will see if the condenser fan comes on.
While cleaning the lines I didn't come across any orifices. Where is it? Drier line?

Former User

The high pressure line gets very hot.

Hopefully the entire problem is due to the condenser fan not running, as this would likely be an easy fix.

srmofo

the high pressure line will get warm ...but not so hot that it burns to touch it...ronj is wrong again.

Air absolutely will not cause high pressures, It will cause poor cooling, but in no way will it cause pressures to go high

sorry the orifice tube is also called the expansion valve, they go by so many different names Im too lazy to remember which manufacturer calls them what

with the symptoms (low and high side pressures high) you described, the most probably causes are ; bad compressor (damaged valves), overcharge (not likely), condenser restricted(inside or outside, bugs and leaves preventing circulation), fans not operating, expansion valve stuck open, clogged reciever/drier, or plugged orifice tube

I can put you in touch with a guy here on hondatech that knows his AC **** pretty damn well (thats mostly all he does) and can probably steer you in a better direction than I can without seeing the car in person.

Former User

On a warm summer day in the shade, go run your A/C for 10 minutes and grab the high pressure line where you make pressure readings. It will be hot not warm.

The excerpt below is taken directly from the A/C chapter in the Civic service manual. This should put this point to rest.

srmofo

I said "not so hot that it burns to the touch". me and you probably have a different idea of what hot is, but when he says that it burnt his hand, that is too warm.

And as far as your page reads reads, you failed to point out the fact that the LOW side pressure is high also. Or did you know that? If you want to start pulling pages out of books I can dig out my old ASE AC book and post those. or better yet just look on yours and find the section that that describes high and low side pressures being high.


On top of that those pressures are not abnormally high, yes they are high, but I have seen pressure upwards of 450psi before.

Either way Im done bickering over this, he said it had a vacuum when he charged it so unless he completely fugged up and opened the shrader valve it doesnt have air, OP pm if you want dudes name.

Former User

I completely agree that hot and warm are subjective terms, but I stand by my statement that the high-side line can get very hot. When the compressor pressurizes the refrigerant, a lot of heat is released. That's why this hot refrigerant on the high side must be cooled by the condenser.

Here is your quote that my diagram was addressing: "Air absolutely will not cause high pressures". The diagram I posted clearly refutes this point.

I clearly did consider that the low side was also high. That's why I asked the OP whether his condenser fan was not running during the pressure measurements. Read post #4.

The service manual indicates that abnormally high pressures on both the low and high sides are likely caused by condenser/fan problems. Again, that's why I asked the OP whether the condenser fan failed to run.

The pressures are pretty high when you consider that only one can of refrigerant (I am assuming about 12 oz) had been added to the system.


With all this said, I apologize if any of my comments have offended you. I consider this exchange only to be a healthy debate.

giperbolic

Thank you for all you help. The noise from compressor was a messed up (locking up) clutch. I swapped clutch from another compressor I had - no more noise. Then I put new expansion valve and drier in and broke all the connections AGAIN, blew air through the lines - no blockage. I coated all the seals in Nylog, assembled it together, pulled vacuum - it held fine this time at -28" Hg for an hour. I filled it up and per DIY on here and with outside air ~75-80F in the evening and recirculation mode I got vent down to 45-50F!

Now the engine is overheating.... but I'm making another thread for that. Thanks again.