New A/C problem

[FoMoCo]

I had a clogged condenser and I installed a new one along with a new drier and O-tube. I removed and drained the compressor overnight and I ran thinner through the evaporator since this would be the only thing to hold oil, I also ran thinner through the lines. I wanted to get the correct amount of oil. I added 1 oz to the compressor and then reinstalled, I then added 6 oz to the drier to get the 7 oz as noted on the label. I did spill just a few drops so I should be just shy of the oil needed. I pulled vacuum and had a leak at the o-tube quick connect, so i resealed and check vac, look better, but my low side quick connector is not to good so it is hard to tell how good the system is. Anyway after pulling vacuum several times I decided to charge the system. I had a partial can that went in as liquid on the high side and then one full can as vapor on the low side, this can went quick. I went to the next can and took a long time and the compressor would only kick on for about 2 to 3 seconds and then stay off for awhile and then kick in for about 2 or 3 seconds again. The low side would be around 45 to 50 and then when the compressor kicks in it would drop very fast to around 25 and kick off. The high side was around 200. The system is working since just past the o-tube the pipe is cold and getting water. Should I try another can, or start over. Is it normal for it to take a long time to add freon? I guess since the compressor is not cycling very long it would take a long time to charge??

 

[itsacrazyasian]

keep adding, you're still low.

 

[franklin2]

And pull the low pressure switch plug off, and put a jumper in the wiring socket to make the compressor run all the time. That will speed things up a little bit.

 

[icanfixall]

I never recommend adding any freon to the high side. Its very dangerous because of the pressures seen on that side. It does sound like you are low on pressures too. Are you using 134 or R12. If the line going back to the compresser gets frost on it you have too much freon in the system and its still cooling as it goes back to the compresser.

 

[FoMoCo]

I added more R-134 and I am sure I am over charged, but still no effect as far as the cycling. Just on for a second or two and then off for awhile. It is hard to get a reading with the system not cycling, but I did change the cycle switch and no change. I did notice it takes a long time for the low and high side to equalize. I know I was overcharged since the equalized reading on the low side was max on the gauge. I released some coolant to get the reading down.

Did I add to much oil? It calls for 7 oz and I drained the system using thinner and compressed air. I even removed the compressor and let it drain overnight

 

[franklin2]

How much freon did you use? With the system totally empty, it's easy to figure out, and also monitoring your high side pressure gives you a clue also. A small can is 12oz. You should have put in 2 cans, without even worrying about adding too much. That would have been 24oz. The 96 I just did cooled well enough on just this much and I left it like that, but I believe these systems can use about 2 1/2 cans or around 30oz and be fine. The 96 had the amount on a little sticker under the hood but I can't remember what it said, but I was way under with just two cans.

 

[FoMoCo]

It holds 2 3/4 or .94 kg. I had 2 1/2 cans and I tried to add some more, I got maybe another 1/2 can which brings me to 3, but I had a leak at the drier. I did the jumper and the high side is OK, it goes to 325 which is not bad since it is over 100 degrees today, but the low side goes to 0 and the evaporator is freezing up starting at the orifice tube. Again it takes a long time to equalize. It seems like another obstruction, I just changed the evaporator, and the 0-tube that came out looked good (no metal). It is not cooling at all.

I might have to put the original evaporator in and try again with a different orifice tube color, I have a red one in currently, maybe a blue???

 

[cpdenton]

What is the pressure on the low side with the compressor kicked on?

 

[FoMoCo]

I am using the jumper to make it kick on.

 

[FoMoCo]

What is the pressure on the low side with the compressor kicked on?

Sorry, the pressure quickly goes to zero with the compressor kicked on.

 

[cpdenton]

Sounds like you are leaking freon back out. Normally it takes about 3 to 4 cans to get the pressures right. You need it to stay right around 40 on the low side.

 

[FoMoCo]

I don't understand "leaking freon back out". The High side is good, so that to me says no clog in the system or a weak compressor, but before I changed the condenser the high side would hit the limit at 425, of course the low side was good then. So you are saying I have a leak after the orifice tube? I did have to bend the lower pipe on the evaporator to get it to mount properly, maybe that is the problem?? it looks ok,

So what would cause the system to have low low side pressures and good high side? The orifice tube?? or to much oil?? or leak??

 

[cpdenton]

Guess I should have asked what both pressures were. I saw that you had about 25 earlier, then now you are dropping to zero. So, what are the pressures on Hugh and low, compressor running?

 

[FoMoCo]

high 325 low 0, and it is freezing up in a matter of seconds

 

[cpdenton]

I would guess with those numbers, you have an obstruction. Pretty sure mine runs at about 40 on the low side and about 200 on the high side. Sounds like the orifice tube might already be clogged, or perhaps the evaporator got mucked up with stuff. Hope you get it figured out soon. Good luck.