Rebuilding my A/C

[Blazin420SHO]

So when I first got my 92 mtx 2 years ago the a/c worked but it didn't work good. Then one day it just started blowing warm air. It had r12 in it and I was talked into putting r134a in without any parts swapping. So now I have both kinds in there. I put a used compressor on the car but haven't done anything to it yet. I need to know what parts I'll need, how to flush it and how to refill it afterwards. I'm assuming I'll need a dryer, compressor, maybe a condensor, seals and cycling switch plus compressor oil. And I would also love some help on where to get these parts. I work on cars everyday but I suck at a/c. Thanks in advance for the help

 

[sperold]

You can mix the R12 and 134A without any issues, although the system is the coldest with pure R12.
If put on a different compressor, did you vacuum-down the system to remove any air that carries moisture during that procedure. If you did, you may be good in every respect. If not, then consider doing that step and topping up the fluid.
All your seals are compatable as they are, you just have to check to see there are no leaks.

I had my system checked out and the shop added a dye to the topped up fluid. Then the yellow glasses worn by the teck guy turned up some leaks on parts that had to be replaced. The total cost was around $200.00 for the labour and added fluid. The part and its replacement cost was extra. Ask a lot of questions before you give your system over to a shop, it should not be an expensive exercise.

The metal parts that bolt to your compressor are no longer available. The lines that run on your inner fender are both available new. Your parts will come from 4-seasons or Specter (?)

If you buy a new compressor, you need to buy the tube with the expansion valve and be able to prove the system was vacuumed to retain your compressor warranty, but I skipped all that.

If your system died a slow death, then you may get by with a refill and dye-test once you have the vaccum thing accomplished.

 

[rubydist]

That's not quite the whole story. The refrigerants mix fine, but the lubrication oil used in the R12 systems is not compatible with R134A, so you need to get all of the "old" oil out of the system before putting in the R134A. Once you have done that, you can fill with new oil and R134A and be fine.

 

[SHOVNST]

If you need an A/C compressor I have a new NOS Ford unit for sale. Check out my for sale ad for pictures!

 

[Blazin420SHO]

I'm not quite to the point of having all the money to get everything. I'm waiting on the sale of one of my ***** cars. I basically want to do everything myself that I possibly can. I hate shops and all of them are garbage where I'm at. How would I go about flushing out the system? And I read on another forum that I could use pc-1 PAG low 46 viscosity oil when switching to r134a from r12. All my ac components are in good shape and the car only has 125000 on it. I'm pretty sure that either my compressor crapped out or the cycling switch. Either way I put a used, sealed oNE I pulled at a junkyard and installed it but haven't moved on from there. I am gonna get a new compressor, should I get a new dryer as well?

 

[rubydist]

yes, you should replace the dryer any time that the system is opened.

 

[zak]

The A/C clutch is a known weak point, just taking a shim out to reduce the clutch clearance can bring them back alive, worth a shot. But you probably have black death (google black death ford R134a), caused by adding R134a t0 an R12 system without addressing the lubrication issues Fred mentions above. That's going to mean replacing compressor, pressure and vapor/reservoir lines and thoroughly flushing condenser and evaporator (replacing condenser in front of the radiator using a Taurus one used for 134a only may be your best bet, if not be certain all your flushing solvents get back out). If the clutch shim trick gets you going again I would get all the R134sa removed at a licensed shop and then replace it with R12 at a minimum, but buy and install the R12 yourself.

 

[Blazin420SHO]

So basically I'll get a new condensor from a standard taurus at my local junyard, buy a new dryer and I think I'll just go ahead and get a new compressor. And if I need new ac lines, what can I get new and can I use any standard taurus parts?

 

[Blazin420SHO]

Also, if I don't have black death (which I don't think I do because when I had it apart after I evacuated the 134a and put a used compressor in it everything looked clean, but I'll check) would I have to replace the lines?

 

[rubydist]

the only line you are supposed to have to replace is the one with the orifice tube (expansion valve) in it. as long as the other lines do not leak, you will be fine without replacing them, if you know they are clean inside.

 

[Blazin420SHO]

Damn, they don't make those anymore do they? Could I get away without it somehow? Or rebuilt?

 

[luigisho]

You sure? I am seeing parts on rockauto. I haven't researched specific part numbers but you should be able to get an accum/drier somewhere and that should have orifice tube already in it. That's what I would do. I would also crack the thing open and drain everything. Not sure if you can pull vacuum and get everything out of the compressor casing. Should not have mixed stuff in there. That's rookie 101 stuff

 

[rubydist]

you can always get the "orifice tube repair kit" which allows you to cut out the old orifice and put in a new one - those are still available.

you can also take off the compressor and turn it ports-down so the oil drains out. then pour in the correct amount, and you know you have the right quantity of the right stuff.

 

[luigisho]

you can also take off the compressor and turn it ports-down so the oil drains out. then pour in the correct amount, and you know you have the right quantity of the right stuff.

That's what I would do, and get some o rings for the compressor ports where it meets the tubing/manifold. Should be able to source those pretty easily. A little bit of work but it should be done thoroughly so you don't have to keep messing with it.

 

[LOUDSHO92]

We have what lines you can replace, compressor and the R134a upgrade switch: http://www.shosource.com/catalog/index.php?cPath=61_74

 

[Blazin420SHO]

I will be getting everything I can get from the sho source, always do. I didn't realize the orifice was in the dryer tube. I'll get everything together and let yoh guys know if it all works out or if I fail lol

 

[LOUDSHO92]

I converted my 92 to use R134a by just pulling a vacuum to remove the old stuff and using R134a.

 

[itwonder]

If you go to R134A, you either have to change the oil to the type compatible with R134A, or use a conversion kit that attempts to encapsulate the old R12 compatible oil so that it does not cause acid formation when it encounters the R134A. I would stay with R12 unless you are changing everything. R12 works better, and it is still readily available in old cans for around $25 a can if you shop. Craigslist is best; ebay is more expensive.