Whoops. So there is. But, it's an effective product and my system is still sealed and has pressure.

 

Just a couple of A/C question since I didn't want to start my own thread...

So I read this thread and more or less followed the directions.

My car HAD been professionally converted to 134a with PAG oil

I removed the compressor, dumped it out and flushed it with ester, replaced the dryer
Filled the 3oz of ester oil into the compressor and dryer, and filled the system with 152a as per this thread.
My a/c blowes pretty cold but the compressor makes a LOT of noise, like it's louder than the engine. It also seems to put more load on the engine than it should, but this is hard to mesure.
How bad is it that I left some PAG oil in the lines, evap. condenser? is it going to destroy the compressor? or just not cool correctly?
If i do destroy my compressor and have to change it, what is the best way to flush the system? alcohol or acetone?
Can I mix a little 134a with the 152a? Can i put a charge of ester with 134a into my system to hopefully quiet the compressor down?

 

Dang it, and I just spent $80 on a 6-pack of Freeze-12. Ah, well, still need to get that es12a out of the FC, it's sorta working now, but will truly suck (like last year) when the temps hit the hundreds. At least it proved that the system is sealed by staying put all winter, which is sort of the reason I used it first, rather than the more expensive Freeze-12. My house is at the south end of DFW airport, so I feel you, jackhild59.
Going to try the R152a in my '70 Cutlass, I think. Need a new dryer, have all new barrier flexible hoses, and was running es12a a while back (yes, I thought it was awesome once, too) somewhat successfully until I kinked a hard line and cracked it, since replaced. Can't use R134a due to the POA valve without either having it adjusted, which apparently can be done, or replacing it with a cycling switch, which I don't want to do, because there's nothing wrong with it, other than being tuned for R12.
Good info - hard to get straight answers about AC sometimes. Thanks!

 

I'm not expert but you will **** your compressor up like that

if I were u I will take it out and use brake cleaner (lots of them) and blow it thru every single line and core and condenser, flush the compressor 10 times and use a new drier(again)

 

The problem with PAG is that it reacts chemically with everything. Chlorine and water vapor and the old mineral oil lubricatnt all react with PAG to create chemical reactions that leave acids and/or black sludge in the system.

The experts say PAG should never be put in a system that once had R12. They say you can never get an R12 system clean enough to use PAG. If that's true, you may already have a problem.

OTOH, there is a *new* PAG called double end capped PAG that is much less reactive and is marketed for use in conversions. Guys out in the field are not convinced.

You can mix PAG and ESTER so this is not the source of your problem. Likely residual mineral oil, moisture and chlorine are combining to create crap in your system. You should really flush it and replace the drier. I would also get a different compressor, that one sounds like it is coming apart inside. Go back with ester and R152a or Freeze12.

 

ok cool, as soon as this compressor lets go and I have to open the system up anyway I'll flush it. I'll probably stick with 152a.
What is a good chemical to flush with? acetone or paint thinner?
i was thinking that in combination with an air compressor would be more cost affectave than can of brake cleaner.

 

I used this product when I flushed the hard lines:

http://www.ackits.com/c/Flush/Flush+...s+-+Hecat.html

It's non-toxic and I worked fine for me. I used this tool combined with compressed air to flush the lines.
For flushing the compressor, you must remove the compressor, do not try to flush the inside of the compressor with any chemicals. The product mentioned above is fine for cleaning the outisde.. With the compressor out, get a small tub or bucket to collect the oil. Turn it upside down and let the old oil drain out. Once as much of it is out, set it down and fill with 2oz of Ester oil, rotate the shaft 20 times, then dump the oil in the container. Repeat this three times or until the color of the oil coming out is the same as the new oil and no crud is seen. Have some paper rags handy to wipe up any spillage and clean up with A/C flush fluid on the outside of the compressor only.

http://www.aircondition.com/tech/questions/25/

 

I'm working on my AC and just want to subscribe to this thread.

 

Don't let the compressor trash the inside of your system. You will clog the condenser with metal debris. That makes the job much more involved. Get ahead of the disaster.

 

I have all my parts in hand...well minus the compressed air itself. I take the cap off my high side to find that the adapter I ordered does not fit and the fitting that is on there is the same size as my adapter. I thought that perhaps the car had been converted, but the fitting looks very factory.



What does this mean? Is my job easier..or harder?

 

The schrader valve cores have to come out first, otherwise, the new conversion fittings won't fit or work. The tool is a $5 item at any auto or bicycle store. The tool is like a small screw driver and works the same way. Insert into the valve and unscrew the valve core counter-clockwise. Don't force the tool; if it's stuck, try using some penetrating oil; you don't want the valve core or remnants stuck in the valve.

You need to remove the cores for both the high and low-pressure fittings. The conversion fittings have their own valve cores already installed.

 

Looks factory to me.
As I recall, there are a couple different size high-side fittings. You probably just got the wrong one. I believe the RX-7 one is the smaller of the two available sizes, but I would have to check. Mine already has R134a fittings on it, or I'd take a look. I had several conversion kits on hand to choose parts from when I did mine.
One quick way to check is to take the cap for the high side fitting with you to the parts store to compare, if you can find a store that still has conversion kits (they may have them "in the back." Don't be afraid to ask. My local O'Reilly Auto lets me paw through their pipe, hose, and tubing fittings to find what I'm looking for, for example.

Also, what cluosborne said - the Schrader valve inside the fitting has to come out first - it just unscrews, exactly like the same type of valve in a bicycle or auto tube/tire.

HEre's one type of the tool. This one includes thread-repair bits for the typical tire valve stem as well:

There are also one with screwdriver handles.

 

I am so confused after reading all of this....... I have an 85 se and the air blows hot. I don't know what was or is in the compressor. I looked up the side taps y'all were talking about. What hoses do I need to hook it up with? How much do I put in? Which valve does it hook to? Does it have to be purged of whats in it now? Just put it in plain simple steps and terms. I know I sound stupid, but I'm really not. I just don't know about the AC procedure and don't want to blow myself or my 7 up.

 

Any easy solution explanetion for an FD? great post. Thanks

 

subbed, cause this is GREAT info!

 

Just wanted to post here and say thanks, I swapped my rx-7 over after finally replacing the last bad component (a faulty compressor) and fixing all the leaks and I now have had ice cold air for 3 weeks, literally:



I think the gauge is off by about 1 degree as it didn't ice up after 90 minutes of blowing this temperature, but it really does feel like 0-1*C. Before I turned the A/C on I ran the fan on high for 5 minutes on the highway until I couldn't take the heat any more, it was blowing 34*C.

I replaced the expansion valve as part of my troubleshooting and I think I set the bulb location a little bit off because the temperature seems to be lower than I would expect, but as I said, it isn't icing up so it seems good to me

 

That is the low side, no?

The high side should be down from there along the frame rail, and IIRC it is 3/16", while the low side is 1/4".

 

If anyone needs an adapter for the high side port to connect a manifold gauge hose to, here it is:

 

I am using the yellow jacket equivalent of that adapter and it's great. I find the brass is a little hard to thread on to the aluminum with my hose attached so I thread it on about 1 full turn by hand with no hose (since it has a valve depressor in it do not thread it on all the way) then attach my hose, then thread it on the rest of the way. Helps prevent cross-threading

 

Dang.
I did my FC this past weekend. Nowhere near that cold, but I'm happy with 60 degrees F at the center vent when it's 102 outside. Way better than the Envirosafe stuff I was using, with the added benefit of not being extremely flammable.

 

102*F = 39*C and 60*F = 15.5*C, consider how much the air is heated before it gets to the evaporator and you are probably dealing with 45-48*C air that you have to cool down. Your air temp is then about 14 degrees higher than mine and your vent temps are about 14 degrees higher as well. Seems pretty reasonable to me, you just need to move to a colder climate

Also, I tried red tek before this and was unable to get the vent temps below 7-12*C under ANY conditions (but also, this was before replacing the expansion valve and before the compressor failed and was replaced so it isn't a perfect comparison), red tek is a hydrocarbon based refrigerant just like enviro-safe. It is my personal belief that R152 is superior

 

Oh, I know, but I'd really love something a bit closer to 40*F. A lot to ask at 100+ degrees F, I suppose, and the Envirosafe couldn't do it. That stuff was merely OK until 90F - past that, not so much. At noon on a 100F day, it was cooler to open the windows.
I'd like colder, but this will work.

 

How would you lubricate since r152 doesn't contain oils? PAG oil? What weight works best?

 

Same way you do with any refrigerant, since none of them contain oil. Jack said R152 worked with both PAG and Ester oils

 

I would use Ester oils and NOT PAG for a system that used to have R12 in it.