Diagnosing A/C Problems

[Reklaw]

I did not see anything specific to diagnosing A/C problems so I thought I would post one here.
2004 XLS.
Last year I discovered a terrible leak around my compressor and replaced it and the dryer. I pulled a vacuum for at least an hour, maybe 2(i can't remember). Then refilled and had cold air for a little while. I don't know if the system stopped working over time or if it stopped all at once over the summer because around the same time the control for my blend door stopped functioning and all i was getting was hot air. I had re-checked the system pressure at the end of the summer last year and it was still good. However, I noticed that my low-pressure lines were not cold which was leading me to believe that maybe my orifice tube was clogged which meant that maybe my accumulator/dryer went bad?

I just wanted to see if anyone had any advice before I got the system emptied so I could work on it. Please if anyone has any advice I look forward to hearing it, and if there is a thread I missed to read up on or this should have been posted elsewhere let me know and I will correct.

 

[imp]

I did not see anything specific to diagnosing A/C problems so I thought I would post one here.
2004 XLS.
Last year I discovered a terrible leak around my compressor and replaced it and the dryer. I pulled a vacuum for at least an hour, maybe 2(i can't remember). Then refilled and had cold air for a little while. I don't know if the system stopped working over time or if it stopped all at once over the summer because around the same time the control for my blend door stopped functioning and all i was getting was hot air. I had re-checked the system pressure at the end of the summer last year and it was still good. However, I noticed that my low-pressure lines were not cold which was leading me to believe that maybe my orifice tube was clogged which meant that maybe my accumulator/dryer went bad?

I just wanted to see if anyone had any advice before I got the system emptied so I could work on it. Please if anyone has any advice I look forward to hearing it, and if there is a thread I missed to read up on or this should have been posted elsewhere let me know and I will correct.

@Reklaw
Check clutch cycling rate. If compressor turns "on" and quickly turns back "off", and given normal amount of charge present, the Pressure Cycling Switch may be faulty, and should be checked. imp

 

[c_monster70]

I did not see anything specific to diagnosing A/C problems so I thought I would post one here.
2004 XLS.
Last year I discovered a terrible leak around my compressor and replaced it and the dryer. I pulled a vacuum for at least an hour, maybe 2(i can't remember). Then refilled and had cold air for a little while. I don't know if the system stopped working over time or if it stopped all at once over the summer because around the same time the control for my blend door stopped functioning and all i was getting was hot air. I had re-checked the system pressure at the end of the summer last year and it was still good. However, I noticed that my low-pressure lines were not cold which was leading me to believe that maybe my orifice tube was clogged which meant that maybe my accumulator/dryer went bad?

I just wanted to see if anyone had any advice before I got the system emptied so I could work on it. Please if anyone has any advice I look forward to hearing it, and if there is a thread I missed to read up on or this should have been posted elsewhere let me know and I will correct.

IMO. Anytime the system is opened the orifice filter should be replaced.

Assuming the system is fully charged then I think you're on the right track. However, aftermarket compressors are notorious leakers, so I'd make absolutely sure the system is fully charged before doing anything else. After that imp's advice would be a good second step prior to tearing the system back apart.

 

[Reklaw]

Thanks c_monster and imp. Yes, what has set me down this path is that the system is fully charged and as there is a little die in the system I did look at everything with the UV light this morning and did not see any leaks anywhere. Before I replaced the failed compressor it was evident that the compressor failed and was leaking. I did not replace the orifice filter because of course it was stuck and i was afraid of breaking it but I guess i'm going to just have to break it and use a long screw to grab it and pull it out, seems like that is what everyone does.

As far as imp's advice, I will double check tomorrow or Friday when the weather is sunnier and hotter here in southern Pennsylvania. I'm fairly positive that my compressor is not cycling off quickly, hopefully I get a chance to check it in the next few days.

 

[plasticseng]

Thanks c_monster and imp. Yes, what has set me down this path is that the system is fully charged and as there is a little die in the system I did look at everything with the UV light this morning and did not see any leaks anywhere. Before I replaced the failed compressor it was evident that the compressor failed and was leaking. I did not replace the orifice filter because of course it was stuck and i was afraid of breaking it but I guess i'm going to just have to break it and use a long screw to grab it and pull it out, seems like that is what everyone does.

As far as imp's advice, I will double check tomorrow or Friday when the weather is sunnier and hotter here in southern Pennsylvania. I'm fairly positive that my compressor is not cycling off quickly, hopefully I get a chance to check it in the next few days.

It's not unusual for a failed compressor to clog the orifice tube with shavings. It is an inexpensive part that needs to be replaced anytime you have a component failure. It can sometimes be a pain to get out, but the system just won't perform with any kind of debris in it.

After a compressor failure, the whole system needs to be flushed out also. Changing the orifice tube won't fix it for long. Once any kind of shavings break loose from the condenser, evaporator, etc, they will clog the orifice and you will be right back where you started.

I've been to Glen Rock / Shrewsbury on business a few times. You have some beautiful farm land up that way.

 

[Reklaw]

I've been to Glen Rock / Shrewsbury on business a few times. You have some beautiful farm land up that way.

Yes, Born and Bred here. Moved away for a few years but I don't plan on leaving again.

Anyway, temperature here is about 75 right now and my compressor is definitely cycling so it look like my first step is to check out the pressure switch. Plasticseng, believe me, I purchased the orifice tube but when i couldn't get the old one out i just gave up and put the system back together. I'm fairly positive that it was just the seals on the compressor that failed so i'm stilling hoping things are not clogged up.

 

[Number Twelve]

The best I can do is confirm what everybody else said. The last time I did a car compressor, the first 3 rebuilt compressors leaked, each one at a different place. And the orifice tube? I've never gotten one out in one piece. You just have to assume it's going to break and think about how you're going to get the pieces out.

 

[Reklaw]

Hey Guys, I did some more advanced checking into my issue. Hooked my manifold gauge set up and found the low side pressure at 90. Obviously this is high but I don't know what the cause is. I did some googleing and it appears maybe it is the refrigerant control valve or something in the compressor. Anyone have any ideas?

 

[Joe in NY]

Could be weak compressor, orifice is wide open, if you have rear A/C could be that the TXV is wide open (however this would flood the suction with fluid be cold). What was your high side ?

 

[TechGuru]

I have a trick for getting orifice tubes out, I apply 150PSI of air in the low side to push it out. STAY OUT OF THE PATH, IT COMES OUT LIKE A BULLET!

As for compressors, I buy OEM Motorcraft's from salvage yards, you can get them on ebay cheap.

I'd never buy a reman/rebuilt compressor, if you don't use a used motorcraft I would buy a brand new motorcraft or a brand new 4seasons.

 

[lincolnshibuya]

I replaced my orifice tube 3x and I only used a long nose plier to pull it out, there's even a tool you could rent in parts store if you want it easier but the plier will do.

with that high pressure on the low side the suspect could be a bad compressor and/or open orifice tube but we need to know what your high side pressure. If the are both high then it's overcharged which will not cool at all.

on some models there is a pressure regular control valve (like on my LS and Jaguar S-Type) which gets clogged (works on high rpm but idle due to high low side and normal high side) and needs to be replaced but on the explorer there's none.

I have bad luck with 4seasons, they don't last that long compared to Motorcraft, the 2nd replacement I have is a used one from the junkyard with 185k miles and still functions likes a champ. My 03 navigator with 220k and 98 Continental with 145k also works fine. I have bad luck with the motorcraft compressor on my mountaineer since it exploded at around 105k miles and sent a lot of debris in the system.. this is my 2nd set of condenser and accumulator/drier too.

There's a also a filter at the rear ac which you access outside (near the rear driver side wheel) and that needs to be replaced too. It's a filter prior to the rear expansion valve.

 

[Reklaw]

Thanks for the replies everyone. The high pressure was low. Like around 100. I'll hook it up again today to verify the numbers and post on here. From what it sounds like though I will have to get the system evacuated so I can crack it open.

 

[Reklaw]

Ok everyone. Thank you for helping an idiot that needs to be paying attention to what he is doing. First off, my Explorer does not have rear air and I have the manual controls.

Now, I just warmed up the Explorer, hooked up the gauges and realized I was doing the diagnostic check wrong. I was opening up the valves underneath the actual gauges because in my mind the pressure had to flow through there. I read my instructions and realized I was doing it wrong so I shut those valves so i could do this properly.

So, my low pressure is reading 30-35 and high pressure is reading 100-125. It's about 90 degrees outside.
My compressor was cycling but not as often as i noticed it was the other day. Also, when my compressor shut off the low pressure reading jumped way up quickly. I know you guys will tell me what that means but i'm going to search for that in the meantime.

 

[Joe in NY]

Procedure for checking pressures:

Driver window part way open (like half way), MAX AC selected, fan on MAX, temp set to Coldest, engine rpm @ 1,500 rpm. On a 90* day at idle it shouldn't cycle at all. At 1,500 rpm you should expect some cycling. (Long on, short off)

Also, when the compressor cuts out the low pressure is going to rise quickly, as it should.

 

[TechGuru]

I have bad luck with 4seasons, they don't last that long compared to Motorcraft, the 2nd replacement I have is a used one from the junkyard with 185k miles and still functions likes a champ. My 03 navigator with 220k and 98 Continental with 145k also works fine. I have bad luck with the motorcraft compressor on my mountaineer since it exploded at around 105k miles and sent a lot of debris in the system.. this is my 2nd set of condenser and accumulator/drier too.

Was this 4Seasons "100% new" or "re-manufactured/rebuilt" ???

Personally, I do not see how one can rebuild a scroll compressor... hmm maybe that's why I'm only seeing them in NEW on RockAuto...

New Motorcraft $307.79 | http://www.rockauto.com/en/moreinfo.php?pk=1126581

New 4Seasons $164.89 | http://www.rockauto.com/en/moreinfo.php?pk=1251888

Used Motorcraft $35.50 | http://www.ebay.com/itm/Ford-Explorer-2002-2003-2004-A-C-AC-compressor-02-03-04-/292067136010

 

[imp]

@TechGuru
Is there any compilation of compressor usage as to type: Scroll, Axial-Piston, or other? Only rebuild I could imagine on a scroll would be bearings, which one could guess would be a critical alignment issue if worn out. imp

 

[Reklaw]

Joe in NY. The only part of the diagnosis procedure I did not do was rev the engine to 1500 rpm's. My low pressure line is also not cold at all which it should be and my high pressure line is very hot as i would expect.

 

[TechGuru]

Here is what my pressures look like at idle, max a/c full fan, about 75 deg out.



R134a is supposed to be filled by weight not pressure, but here is a chart for reference.

 

[lincolnshibuya]

Was this 4Seasons "100% new" or "re-manufactured/rebuilt" ???

Personally, I do not see how one can rebuild a scroll compressor... hmm maybe that's why I'm only seeing them in NEW on RockAuto...

New Motorcraft $307.79 | http://www.rockauto.com/en/moreinfo.php?pk=1126581

New 4Seasons $164.89 | http://www.rockauto.com/en/moreinfo.php?pk=1251888

Used Motorcraft $35.50 | http://www.ebay.com/itm/Ford-Explorer-2002-2003-2004-A-C-AC-compressor-02-03-04-/292067136010

the 4seasons is new, along with new condenser, orifice tube and accumulator. It didn't leak, the bearing is making noises (not the clutch pulley bearing) luckily I pulled it out before it will explode. the noises it made is not fun to hear..

 

[TechGuru]

the 4seasons is new, along with new condenser, orifice tube and accumulator. It didn't leak, the bearing is making noises (not the clutch pulley bearing) luckily I pulled it out before it will explode. the noises it made is not fun to hear..

How much oil did you put in it and what kind?

Calls for 9oz of PAG46 without rear a/c and 13oz PAG46 with rear a/c.