Metal in orifice tube

[torchroadster]

My 93 Explorer (R-12) had a leak in the A/C which I traced to the evaporator. Using a leak detector with the probe in the blower motor resistor hole it gave a strong positive leak indication. Although when I removed the evaporator there weren't any visual signs of a leak. Maybe I'll try to pressure test it to be sure. There were a lot of leaves and grunge in there - so wonder if there is anyway that stuff would give a false positive?

But my real question is about the orifice tube - when I removed it I found lots of metal chunks in the filter screen. What does this mean? Bad compressor? If so what other things do I need to clean and replace? The compressor seemed to run OK before the leak. Perhaps leftover junk from an old repair?

Also I probably need to convert to R-134 in the process - so I've been reading up on that process. Looks like major $$$ all together.

 

[BrooklynBay]

How long was that orifice tube in there? Was it the original one? It's possible for some metal fragments to accumulate over a period of time (assuming that it was the original one).

 

[torchroadster]

How long was that orifice tube in there? Was it the original one? It's possible for some metal fragments to accumulate over a period of time (assuming that it was the original one).

I really have no idea how long the orifice tube was in there. I've owned the truck for about 15 months so at least that long - beyond that I don't know.


It looks pretty bad - I'll try to post a pic.

 

[torchroadster]

Here's a picture of the orifice tube with all the gunk in it.

I cleaned it off and took a closer look - it seems that most all of the debris is non-magnetic and pretty soft. Like a seal or something but not sure. I would really appreciate the advice of someone more experienced at what I might expect to see and what it means.

 

[shamaal]

Black Death RIP.

Sometime in the past the teflon seals in the compressor broke down. This may have happened with this compressor or a previous repair and they neglected to adequately flush the system/replace components.

Cost for upgrade from R12 to R134a is less than having a shop repair the system plus you get a whole bunch of nifty tools like gauges and vacuum pumps.

There's a number of paths depending on how much risk you are welling to accept.

Minimum:

1. Change accumulator and orifice
2. Remove Compressor and drain oil
3. Change o'rings
4. Flush condensor
5. Fill with PAG 100 oil - 43 oz in compressor 3 oz in accumulator and 2 oz in condensor. (Total 7 oz)
6. Evacuate and fill system with R134a

This assumes problem isn't in your compressor. If this problem is from your current compressor, the compressor needs to be changed. In the evennt of black death it is recommended that the condensor and hoses be replaced as this crud cannot not be completely flushed from system. Use your best judgement.

Good Luck!

 

[ma96782]

IF you're gonna switch from R-12 to R-134a:

IMHO......IF the system was not functioning….you’ll be ahead of the game.…if you take it to a pro. Find out, if it only needs to be topped off or, if there is a leak or, if the compressor is up to the job. A pro, can test the compressor and usually has the tools to test for leaks, using a dye or with an elec. sniffer. IF you decide to proceed w/ a DIY CONVERSION job, you’ll now KNOW what part(s) will be needed and the system will still need to be evacuated anyway. The machine to recover R-12 is expensive and it is against the law to vent R-12 into the atmosphere. So, let the pro do that part.

Once void of refrigerant......you could DIY the parts replacement part. *IF you know that a part is bad……now, will be the time to replace it. IF the compressor has failed, you‘ll need a new one and YOU’LL NEED TO FLUSH.*

The usual conversion, will require the removal of the accumulator, orifice tube, and old compressor (w/clutch). Drain the oil from the compressor and note the amount. Drain the oil from the accumulator and note the amount. Dump the old accumulator and orifice tube, buy new ones (compatible w/ R-134a). The old compressor can be re-used if serviceable.
__________________________________

Hummm……To FLUSH or NOT, you decide.

One of the reasons for a flush of the remaining components.....is that, as much as possible, you want to clear the “crud” and old oil out of the system. I wouldn't want to mix mineral oil used in an R-12 system with the oil needed for an R-134a system. But, that's just me.

So…..the evaporator and condenser can be flushed in place (or removed and flushed)......be careful. You could also flush the lines.......but, flushing a line w/a muffler is not recommended. So, you could buy a replacement hose w/ a new muffler or skip that line/part.
_________________________________

As long as MOST of the old mineral oil is removed and IF there was NO compressor failure…..according to the Haynes book: "Unless the vehicle manufacturer - or the aftermarket kit instruction sheet specifically recommends flushing the system during the retrofit procedure, you can assume that flushing is not necessary (Readers who obtain the SAE's J1661 document will note that it recommends flushing before retrofit. However, you can disregard this information because the SAE no longer believes that flushing is critical to a successful retrofit.)"
__________________________________

Anyway.....replace all the old "O" rings with new green "O" rings. Use Nylog as a lube (ask the parts guy for the correct one).

As for AC oil….use the correct compatible type and weight, keeping in mind the particular manufacturer of the AC system and refrigerant type. Oil is added into the individual parts as they are installed. How much oil? The answer varies. A good book on the subject will help.

Install all of the parts and connect up all of the lines and hoses. Once everything is back into its place..........you'll need to add on the new R-134a adaptors and label the system w/ a R-134a conversion sticker (so, the next guy will know).

Then proceed with your re-charge procedure.

Full Re-charge:

http://www.explorerforum.com/forums/...d.php?t=158183

Note: System pressures will vary between mfns and applications (again, a good book will help).

Ford Conversion Notes:

My '94 Explorer (w/ factory R-134a) used a blue orifice tube. I’ve heard that previous years (R-12 systems), used a red orifice tube. Normally......I figure, IF the factory system worked well w/ whatever colored tube......then, I should replace the tube w/ a like colored tube. Thinking - that the orifice color, indicates a certain sized hole. But, in this case (R-12 to R-134a conversion) a switch from red to blue orifice tube might be the correct choice.

Also, check that the low pressure switch is the correct one for your application. NAPA lists different part numbers for an R-12 vs. R-134a system (remember to also check the elec. connectors).

Shamaal said:

The switch on the accumulator controls the clutch on the compressor. When the system pressure is less than 24.5 psi the clutch is disengaged. When the pressure is greater than 43.5 psi the compressor clutch engages.

And, as a COMPARISON ONLY.......the Haynes book says ('94 Ford Explorer w/factory R-134a system)........at ambient air temp of 80 degrees F, hi velocity fan in front of the condenser, 1500 RPM.........22-50 low side and 160-250 high side pressure. Capacities: oil 7 oz and R-134a 2.25 lbs (36 oz).**Conversion capacities will differ, for a R-134a conversion, I've heard figures anywhere from 60-90% of the R-12 charge was good. **
_________________________________________________________________

Aloha, Mark

PS.......In your case....FLUSH!!

 

[torchroadster]

Thanks for the replies guys. That's what I was afraid of. I did a bit of a flush today on the condenser with alcohol and compressed air - not much stuff came out. The lines look pretty clean at both ends. I'm fairly well set up to work on A/C - I have a gauge set and the venturi type vacuum pump. What's the best way to do a reasonably proper flush at home? I've seen aerosol type flush kits - is this the best approach?

http://www.acsource.com/index.asp?PageAction=VIEWPROD&ProdID=1245

I'll probably go ahead and replace the compressor and hoses and since the evaporator leak is what started all this that will be new too. The receiver/dryer and orifice tube replacement is a given - so at this point I'm basically trying to save the condenser.

Also my gauges hoses are for R-12 Are these the hoses I need? http://www.acsource.com/index.asp?PageAction=VIEWPROD&ProdID=836

 

[ma96782]

How to flush an AC system:

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=9172



Dead Link Removed


Cheap way

http://www.autozone.com/R,NONAPP312/store,1169/shopping/accessoryProductDetail.htm


Expensive way

Dead Link Removed


Aloha, Mark

 

[torchroadster]

Mark:
Just want to confirm something:

you wrote:
_____________________________________________________________
Ford Conversion Notes:

My '94 Explorer (w/ factory R-134a) used a blue orifice tube. I’ve heard that previous years (R-12 systems), used a red orifice tube. Normally......I figure, IF the factory system worked well w/ whatever colored tube......then, I should replace the tube w/ a like colored tube. Thinking - that the orifice color, indicates a certain sized hole. But, in this case (R-12 to R-134a conversion) a switch from red to blue orifice tube might be the correct choice.
_____________________________________________________________

I should install a blue orifice tube from a later model Explorer when converting to R-134 not the original red one?

I bought the parts yesterday and started putting it all back together tonight. I got the evaporator and accumulator installed. Tomorrow will be the compressor and compressor hose. I plan to flush the condenser before I finish but don't have flush gun yet.

By the way you can attach the accumulator to the evaporator off the car and get it reinstalled without too much trouble. I removed the right inner fender and that makes things much easier.

 

[ma96782]

I should install a blue orifice tube from a later model Explorer when converting to R-134 not the original red one?

Further thoughts on the subject......

What color orifice tube to use on a FORD?

http://autoacrepairs.com/ford_orifice_tube_application9202.htm

------------------------------

GM White .072 Orifice, Single black o-ring

Ford Blue or Black .067 Orifice, 2 Green o-rings

Ford Green .052 Orifice, 2 Green o-rings

Ford Red .062 Orifice, 2 Green o-rings

Ford Orange .057 Orifice, 2 Green o-rings

GM, Opel & Volvo Black/White or Red/White .072 Orifice, Single black o-ring

Ford Brown .047 Orifice, 2 Green o-rings

Chrysler, Jeep, Eagle & Dodge Purple .062 Orifice, 2 Green o-rings

GM, Volvo & Opel Yellow/White .062 Orifice, Single black o-ring

GM Yellow/White or Red/White .062 Orifice, Single black o-ring

GM, Geo & Opel Orange/White .057 Single blacl o-ring T-Tab

Audi & VW Gray/White .072 Orifice, Single black or purple o-ring

GM Yellow/White .062 Orifice, Single black o-ring no tabs

Ford Black/White .072 Orifice 2 Black o-rings

Now, I'm not an pro. Here is my thinking.......the 1st Gen, R-12 systems, used a red.....my '94 with Factory R-134a, uses a blue tube.......so, does that mean that in a 1st Gen w/ R-134a, a blue should be used?

POSSIBLY......remember I did say, "might."

I don't KNOW for sure.......IF, the '91-'93's systems are EXACTLY the same as the '94's system, except for the refrigerant used. In the '94 Explorer, the construction of the: condenser or evaporator or accumulator (not to mention capacity) could have been different (aside from the fact that R-134a is used and not R-12). But, I also mentioned to change the low pressure switch.......NAPA, DOES SHOW different ones for the refrigerant used (R-12 vs. R-134a). Folks have also mentioned the heater manifold (in '94 a heater cut out was added), there have been different reports as to it's effectiveness (on a conversion system).

So......all together, will this be the ultimate set up, for a conversion 1st Gen AC system? Well, I don't have the PROOF........you could experiment, red vs. blue.......and report back......but, that experiment will cost you refrigerant. The FINAL decision is YOURS.

Humm......but the 2nd Gen vehicles uses a red one. Did the AC system change, again?

Aloha, Mark

PS......The accumulator needs to be correct for R-134a........I've heard that the desiccant might be different between a system built for R-12 vs. R-134a.........though, lately things may have changed.........either way.......BEST TO CHECK.

Lastly.......the system capacity for R-12 will differ from that of a system using R-134a......so, keep a close eye on the pressure gauges and temps........to get the BEST RESULTS. Record the final readings and put that conversion sticker on.........for the sake of the next guy.

 

[torchroadster]

Thanks for the response and the link - it helped out with some other questions I had. Still don't know about the orifice tube for sure. I'm going to ask around some more before I finish up. I'm guessing blue for 94 - Ford went back to red in 95 but by then I wonder if they optimized other parts of the system? I'll let you know what I find out.

I have an adjustable low pressure switch so I'm staying with what I've got on that and adjust as needed.

 

[Maniak]

Another type of orifice tube to look into is the Variable orifice tube. I've tried the regular ones on a few conversions and found in southern AZ that at idle the a/c just didn't work that well. I then found Variable orifice tubes which raise the pressure when at idle help make the a/c work better at idle.

It at least worth looking into..

~Mark

 

[ma96782]

Some notes, for when you're doing the re-charge:

Assume: There are NO LEAKS, the AC compressor & clutch, radiator fan & clutch, are up to the job and the system has been evacuated........

When you're re-charging the system......to start, charge it (into the vacuum) with whatever it'll take w/ engine “off.”

Then, set up a high velocity shop fan in front of the condenser and let her rip (highest speed). Turn on the engine, running at 1500 RPM, set the AC (max), *blower fan speed set at highest speed, doors closed and windows up, 10 mins. running to stabilize the system. *I have noticed that a lower blower fan speed, will get you lower temps. And, the HAYNES book says, blower fan speed at lowest speed, for the "Final Performance Test."

Continue to fill the system (w/ R-134a) to 60% of the R-12 charge. Sometimes, to help get the 60% in there, you might need to use a jumper at the low pressure switch connector, to get the compressor working. Once you get the 60% in the system, remove the jumper, reconnect the low pressure switch and observe that the clutch is working. IF the clutch doesn't energize, you may need to add a little more refrigerant (or the low pressure switch may be broken). IF you see that the compressor clutch is working. Check the ambient air temp and compare it w/ the vent temp. At an ambient air temp of 75-80 degrees F, you're looking for a 35-45 degrees F at the vent (about a 40 degree F difference, though close enough is good to). If you don't get the temps you want.....continue to add refrigerant (in the past, anywhere from 60-90% of the R-12 charge was reported to be good).......mindful that too much is no good and too little is no good......so, watch the pressure and temp readings.

Ambient air temps are taken 2” in front of the condenser. Vent temp is taken at the dash vent closest to the evaporator (usually one of the center vents).

And, IF the system still runs a little hot......you may have to go to an additional elec. fan in front of the condenser or a larger high-efficiency condenser.

Aloha, Mark

 

[torchroadster]

Thanks for the tips guys. I've seen the variable orifice tubes - probably a good idea but I don't know of a local source. Anyway I went with the blue one. We'll see how it goes. Most of my driving is on the highway with this truck so I'm not too concerned about idle performance.

I got it mostly all back together today. All I lack is installing the new liquid line, and going through the evacuate and charge process. I need to get new hoses for my gauge set before I go any further. I bought an adapter to tap into the freon cans but it doesn't have the same threads as the R-12 one I've used before. I had been planning to do the charging and evac with the old system fittings and then install the R-134 adapters after I was all done - but looks like I've hit a stumbling block on that one with the can adapter. I needed new hoses anyway but won't be able to pick them up till later this week.

I did come across one surprise during the install. The new compressor won't turn over by hand. Is this normal? I went back to the auto parts store and they had another one, but it was the same way so I kept the original. I put in 7 oz. of PAG-100, about 3 oz. in one side of the compressor and 4 oz. in the other. But that didn't change anything it still wouldn't turn over by hand. I even put a wrench on the small bolt in the center of the clutch but couldn't budge it. Are these really stiff when new? I put the shipping seal back on the back of it and bolted it onto the engine. I need to drive it tomorrow. I left the clutch wire disconnected.

I ran two of the big aerosol flush cans through the condenser. The first can got out lots of gunk, but the 2nd one was nearly clear so hopefully I've got that issue handled. Every other component is new.

 

[ma96782]

IF, I assume that all of the old oil was removed via the flush of the system......then, I believe that you should put half of the oil in the accumulator and the other half in the compressor (rotate the compressor by hand to distribute the oil prior to installation). So, YES, IMHO the compressor should turn by hand.

Aloha, Mark

PS.....As far as I remember.....I turned my new compressor by hand, when I did mine.

 

[torchroadster]

Yep, not sure what's up with the compressor that won't turn over by hand. The instructions with the compressor said put all the oil in it so that's what I did. I'll probably short the low pressure switch and bump the starter a few times to see if that turns it over before going much further. Or maybe I'll just take the belt off and try to turn it with a strap wrench with the clutch engaged.

 

[torchroadster]

It looks like a stiff compressor is normal when they are new.

http://www.acsource.net/acforum/viewtopic.php?t=4569

 

[ma96782]

Thanks for the link and info.

Aloha, Mark

 

[torchroadster]

I just wanted to follow up with my results. I finally got around to finishing this job up a couple weekends ago. Had some delays with a new guage set I ordered, anyway the results were very good.

I replaced everything in the system except the condenser and that I flushed with two cans of flush. When I put it all back together the system held a vacuum well so I evacuated it for about an hour, then put in 36
oz. of R-134.

I'm getting high 30 to low 40 degrees at the center vent. I'm very pleased!

Thanks everyone for all the help and advice!

 

[ma96782]

Thanks for the feed back.

I must say.....you did GOOD.

Aloha, Mark