R-12 Refrigerant swap?

[429CJ-3X2]

My bet is your orifice tube is gunked up.

I agree, although I'm far from an expert. The Sport Trac I now have is the first vehicle I've owned in years that the A/C works in. I'm certain that was the problem with the A/C in the '89 Bronco II I used to have, and my '94 Explorer too. Both showed proper pressures, but only put out warm air. I changed the orifice tube in the '77 LTD II wagon we once had and that fixed it. The wagon was easy, as the orifice tube was in the line right up by the battery. I've never been sure where it is on the Explorers- or how to get to it if it's where I think it is.

 

[arco777]

Many thanks to all who've replied, I will check all the stuff that has been mentioned.

 

[mccoyxx]

the orifice I changed a couple weeks ago on my 91 Ex was a little rough to get to ... its on the passengers side ... I had to remove the air box ... and then I could see the silver lines coming from under the box ... about as big around as a quarter ... I am thinking the joint took a 19mm and a 21mm to break ... as soon as it comes apart you will see the end of the orifice sticking out ... they make a special tool for removal, but my needle noses worked fine ... i pulled the old one out & was horrified ... looked like it was dipped in mud,then oil ... anyways i put a small dab of grease around the new ones o ring & it slid right in by hand ... make sure you put the new one in the same way the old one came out ... anyways I have ice cold AC now and it only took about 40 mins to do ... they say you can take the fender well out and the tire off and get to it that way, but I got mine ok by the air box entry ... hope this helps !!

 

[mccoyxx]

I also had to unplug the wiring harness & move it out of the way ... it wasn't horrible, but was a little tight ... much easier than removing the tire & fender well in my opinion though

 

[arco777]

the orifice I changed a couple weeks ago on my 91 Ex was a little rough to get to ... its on the passengers side ... I had to remove the air box ... and then I could see the silver lines coming from under the box ... about as big around as a quarter ... I am thinking the joint took a 19mm and a 21mm to break ... as soon as it comes apart you will see the end of the orifice sticking out ... they make a special tool for removal, but my needle noses worked fine ... i pulled the old one out & was horrified ... looked like it was dipped in mud,then oil ... anyways i put a small dab of grease around the new ones o ring & it slid right in by hand ... make sure you put the new one in the same way the old one came out ... anyways I have ice cold AC now and it only took about 40 mins to do ... they say you can take the fender well out and the tire off and get to it that way, but I got mine ok by the air box entry ... hope this helps !!

Thanks for the info!

 

[arco777]

I installed a new heavy duty fan clutch and a new heavy duty fan. Didn't notice any difference in AC output.

A new variable orifice tube "for severe climates" and a new receiver dryer along with new O-rings have arrived. Will post again once I get them installed.

Another question. I have read that when the AC compressor fails, the "black death" that follows clogs up your system badly. Is there any way to estimate how much life my AC compressor has left? It's not remarkably clean or dirty, and aside from checking how well it pressurizes the system, I'm not sure how to tell.

Also, I've heard that the black death is a failure mode of the Ford FS-10 compressor, which I believe is stock. Would aftermarket brand new or remanufactured OEM compressors have this same failure mode?

 

[4x4junkie]

I believe Black Death is the result of wear particles from improper lubrication mixing with the oil or whatever other liquid contaminants are in the system. I would think any compressor is subject to this, not just the FS-10.

The decision to replace the compressor I think should be based on what your orifice tube and the rest of your system looks like.
If things are clean (no more than a light-tan to light-gray oily appearance), your compressor should be fine. If you find stuff coated with a dark or black oily substance and/or debris, then the compressor is likely on it's way out (you should replace the condenser core in this case as well, as that debris is next to impossible to get out of it by flushing, and it will just ruin the new compressor too).

 

[arco777]

Thanks, I will check it out and see. Plan is to install the new drier and orifice tube tomorrow, and if the system is clean looking I'll get it recharged Wednesday.

Noticed there is an inline filter ("refrigerant filter") in the AC line on the he front drivers side of my engine bay. Does this ever need replacement?

 

[Maniak]

You will know if you have black death.. Its nasty stuff and plugs up the orifice tube. It is a breakdown of the oil mixed with compressor shavings and hose lining parts. You cannot flush it out without a special machine and special chemicals (last I saw it was $70 in chemicals, not including the machine).

Here is a shot of my orifice tube when I changed it last year (14 months or so ago)..

Black Death on a Variable Orifice Tube by maniak_az, on Flickr

I basically have to change it yearly. I really need to rebuild the entire system as the compressor has been noisy for many years but I've been able to keep the system running well enough for 100F days (not so much on 105F days) by changing the orifice tube yearly.

~Mark

 

[pkn]

msmith65 just reported 15 degrees vent temperature drop after switching from R134a to Freeze 12.

http://www.explorerforum.com/forums/showpost.php?p=3190794&postcount=23

Freeze 12 is not R12, of course, it "is nothing more than a blend of R134a and HCFC 142" http://www.ebay.com/gds/Freeze-12-Refrigerant-R134a-/10000000005615895/g.html

However, I've never heard or read of R134A working better than R12 - no matter in retrofitted or in R134A-designed systems, and I did hear and read a lot of complaints about R134A. My impression is that it's a common knowledge that the only good thing about R134A is its "eco-friendliness", whatever that might mean.

And I remember all too well that the whole "ozone is depleting 'cause of freons and we all gonna die" story turned out to be B.S..

I have all-brand-new AC system in my '92 XLT, compressor is brand new and has label saying "Charge with R134A" on it, system is charged with R134A and I don't like it's performance. I'm planning to switch to Freeze 12 as soon as I will have time to work on it (I already have all the needed tools and experience).

 

[Anime]

The "Black Death" is unique to the FS-10/FX-15 and similar multiple piston-type compressors, since they will continue to operate even while they are disintegrating internally. Other types of compressors just seize up and never get to liberally distribute their contents throughout the A/C system when they fail.

If you have a factory '94 system with R-134a, I would NEVER suggest switching to R-12 or anything else. R-12 is more efficient, sure, but it's EXPENSIVE, and technically illegal to even possess without a license.

R134a, even the genuine DuPont stuff (which you can get at CarQuest), is inexpensive, legal for anyone to own and use, and inexpensive. Did I mention it's inexpensive?

I would guess that the o-ring seals in the factory hoses are leaking from age, and the system is low on R-134a, causing the higher temps. You can DIY if you have the system professionally evacuated first, then disconnect all the hoses, replace the o-rings (use the green ones, they are all most auto parts stores sell now, you can get a o-ring kit specific to the Explorer), you may also want to use Nylog to make an even better seal and keep the o-rings from leaking for a long, long time. Then just get a gauge kit and some cans of R-134a, or take it to the shop to have it checked over and R-134a put back in.

I think the "severe duty" variable orifice tube is way overkill. Just the "regular" variable orifice tube or the regular OE one for R-134a is fine. Be sure it gets genuine DuPont Suva R-134a, the cheaper stuff sometimes has leak stoppers/fillers that cause more problems than they solve.

The in-line filter is part of the hose. That hose is pretty expensive on a 94 because it also has an electrical connector to monitor the system pressure. You don't really need to replace it unless the exterior of the filter is rusting apart and a leak may be imminent. It can be a good idea to sand off any rust and use some anti-rust engine paint to prevent that from happening if the hose is otherwise in good shape.