[davebrossi]

So I'm still on only one drive in my 91 164L, and in turning it over to Sutton Autotech (who are not on this forum, so it's not a plug unless you live near by) I did the right thing. Long story short, they caught a lot of mistakes I made, and the engine looks 200% better (not to mention I've now got new valve cover gaskets and all the other recommended ones.) However, the cause of the broken accessory belt that put me into this mess has been determined to be a seized compressor. So while hiding my embarrassment at my own horrible sloppy water pump exchange (they don't like permatex and apparently old gasket removal tech has improved greatly) and, uh, timing woes (1 tooth, 2 teeth, but no red fish or bent valve!) I'm in a bit of a bind;

First the good news; I've ordered a new compressor from Alfissimo (who also gets credit for all the other parts) and its on the way soonish. Also did I mention they've done a wonderful job cleaning up the engine? no more chrome oxidation! :thumbup:

Now the bad; P/O seems to have used Freeze12 (Spelling?) to recharge the system at one point, the fittings are still all R12, and after looking at the expense of a new condensor and other assorted items I've opted to try a product called Red Tek R12a to recharge the system.

My questions are therefore two fold; first, since it's not installed yet, will Red Tek lead to an Alfpocalypse? I know the very basics about the R12-R134a shift, but the R12 Substitution market is something I am unfamiliar with.

Second; since I'm opting to keep the system on that and not replace the other bits that would add quite a lot, Are there any considerations regarding the oil used in the compressor I should be aware of? :sailor:

 

[144]

That Red Tek stuff looks pretty much like a standard hydrocarbon based refrigerant like Envirosafe ES-12. I have not used it in an Alfa system, but have used ES-12 in an old Jeep R-12 system and it worked well. It supposedly works in R-134 systems as well, but I personally have not done that.

It is very important that you figure out if your old compressor self destructed internally and sent the "black death" through the system. If that is the case, you'll need to clean/flush the entire system, otherwise it will most likely not work and destroy your new compressor. It is almost impossible to flush condensers, so that would have to be replaced along with the receiver/dryer as a minimum.

I am not a proponent of getting cheap when repairing an air conditioning system. The new compressor you will get will almost certainly NOT have R-12 mineral oil already in it. It will have R-134a PAG oil already installed. It is not good to mix mineral oil and PAG oil (IMO), although the HC based refrigerant manufacturers say HC is not particular about compressor oil.

So, IMO, if you're set on HC, you should drain and measure the mineral oil out of your old compressor. Then put the same amount of clean compressor mineral oil back into the new compressor . . . after completely draining the pre-installed PAG oil. I'd even flush it some with clean mineral oil to do the best you can to get out as much PAG as possible. A lot of oil remains in the condenser, lines and evaporator, so that's why you have to measure and replace what is already in the old compressor. Excess oil inhibits cooling efficiency.

That said, for a couple hundred dollars more, you can do a full changeover to R-134a with a new and more efficient parallel flow condenser, new receiver/dryer and TXV valve. There's a thread on the BB here with a guide on how to do that.

Maybe someone can chime in with direct experience using HC in an Alfa system.

 

[davebrossi]

...My Credit card is now as hot as that compressor likely became when it broke the first belt. The more I thought about it the more I thought "look, you already embarrassed yourself trying to short cut the Water Pump"

So, in summary two things;

First, yes I should have searched backwards and I'd have seen the VERY helpful how-to on compressors. I apologize

Second, though I couldn't find the correct O-rings (I'll just have to refill every year) I DID order all the recommended items for the full conversion. I'll ask them to flush the system when the time comes. I did NOT replace the POA valve however.

 

[144]

I don't think the difference between the R-134 and R-12 POA valves is significant. I tested the pressure differences and couldn't see any material difference. I still left the R-12 POA in my system and it cools great even with the old POA valve.

Keep in mind that if you use the old R-12 hoses, you'll likely have to top off the A/C at the beginning of the season. Some people say that the old R-12 hoses have enough gunk on them to seal in the smaller R-134 molecules, but I don't believe it. My experience is that you do some seepage through the hoses regardless. However, if the R-12 hoses are in good shape, I'll do with a top-off once a year rather than replace everything with barrier hoses.

Here's the conversion guide:

http://www.alfabb.com/bb/forums/164-168-1991-1995/198765-r-134a-conversion-guide.html

I would advise that the tension of the accessory belt not be anywhere near as tight as the Alfa manual specifies. It specifies a ridiculous 124-135 lbs of tension. 60lbs is usually perfectly adequate to maintain a good grip/no slip. This should considerably lessen the wear on the water pump, compressor, and tensioner bearings.

 

[davebrossi]

Thanks! I believe you entirely on the leakage of the lines, but I also see the 'once a season top up' as a price worth paying. Mainly that's because I can't seem to find a website to source the R134a O-rings from, but hopefully someone might? Or is this a case of "Replace the entire lines while you are it" ? For the record they seem fine to me though, I also thought my water pump replacement and timing belt setup were fine too, so....

 

[Del]

134a O ring sets are available at autoparts stores. That's where I got mine. I also recommend making the complete change, cleaning everything. You don't want to mess up your new compressor. I made the change using Roadtrip's guide, including the new condenser. Pretty easy, although if you are not sure about your mechanical abilities, I'd let the shop do it.

I have to say that the 94/95 LS lines seem to hold the 134a without leaking worth talking about, as the a/c system in my 94LS is still all original, no topping up having been done, and the a/c still works like a champ, as it should, even in the SW with 110F temps. You might look for used LS lines to use, if they will fit. Doesn't hurt to change from what you have.

 

[Gubi]

I've had two Alfas converted from R12 -> R134A. YMMV, but I didn't need to replace the hoses or expansion valves, and o-rings were only swapped as needed from leakage testing. I do need to top it up every couple of years.

Most important thing with R134A is to get the charge level right. If you overcharge it works like crap so it's not a case of "more is better".

 

[davebrossi]

Glad to hear it about the O-rings. I'll ask the shop about the condition of the lines. Man, I can't wait to drive this thing when its done. And I'm now in the price range most spend on a 164 with plenty of new goodies. That said I -am- thinking of naming the car 'naked singularity' or 'gargantua'

 

[Del]

Also keep in mind that people in the BB did come up with a way to drive your car sans a/c compressor if you want to wait on the a/c rebuild (I gather you are in Idaho Falls, won't need the a/c for a while there, lol). In the discussion of helping "Brewtech" with his 164 when the a/c pump bearing failed while on the road, they designed a bracket, w/different serp belt length, for mounting the alt down where the a/c pump had been installed. Don't have the particular BB postings, but search for the "LA to Seattle" postings, maybe 11 pages worth. Those pages describe the work that went into the design.

You can then drive your car to your heart's delight until the weather warms back up.

 

[davebrossi]

I have two other cars to run about in so I'll avoid bypassing the A/C for now. Embarassment over the botched install means I'm making sure it's all done as it should be.

 

[Del]

Be sure to get a copy of the workshop manual if you don't have it, either CD or paper version. I always have one for every Alfa I've owned. Also, peruse the Fiat parts eper on the computer to get a good feel of how the car is put together. Another great site for the 164 is the 164 Digest site, which has more information on that car than you would ever want. Also has a ton of service and repair related posts from the 90's, when the car was first introduced into the US.

 

[davebrossi]

Woohoo! I'm a big fan of manuals, I've got the shop manual and associated documentation on DVD, really need to get into that...

 

[144]

Getting new barrier hoses made is a bigger deal because the fabricator will have to use one or two of the old metal pipe ends. Salvage hoses from an LS? Well, maybe ok, maybe not. If you got them real cheap and they looked good, might be worth the risk.

 

[pinino]

Not too much of a big deal, Nostalgic Air did mine for a very reasonable price. Not changing to barrier hose when doing a R12 to R134a conversion is false economy. According to experts the R12 hose will work for a while but the new oil and hydrogen contained in R134a causes the R12 nitrile hoses to rapidly deteriorate. R134a hose has an extra nylon inner sleeve.

 

[Del]

Thanks for the info on the hoses. I still think even used LS hoses will be better than sticking with the R12 hoses. I'm confident that they would be in better condition than what he has, based on my experience with my LS.

 

[davebrossi]

So just going off Alfissimo, that would be the A/C line with valve and the line from the condensor? 500 dollars hopefully includes a decent lining?

 

[pinino]

Dave, there are three hoses, all different diameters depending on pressure. You can take your existing hoses off and send them to an AC shop to have new barrier hoses made to the same exact length. There are six connectors in all, 4 can be replaced (they are standard generic) and 2 need to be reused: top connector at condenser and connector at dryer. In the picture below the reused connectors are the two with hook shape. Not all shops have the experience of saving old connectors (Nostalgic in FL does). Including shipping we are talking < $150.

 

[davebrossi]

I like the sound of 150 a bit more. Hopefully nostalgic has a website? I'm in the potato republic so I'm going to have to arrange things long distance

 

[Alfissimo Int.]

That A/C line was from alfa and is NLA. I would have them rebuild by a A/C specialist in your area. Look for a MAC certified shop.

 

[davebrossi]

Got used to that with my 81 Vanagon. Glad to see you guys are following this at Alfissimo, that way I know I'm not ordering in over my head when I ordered the other parts from you