90 Legacy A/C question

[Txakura]

The compressor makes a very loud rattling sound when engaged, I thought maybe low on freon/oil might make that noise. In my shop we have a manifold and several pounds of R12.

 

I have never serviced A/C. There is no procedure in my Chiltons. Most searches here talked about the conversion to 134a. Before I waste extremely rare and valuable R12 to a line leak or bad o-ring...

 

what should I see for normal pressure on the gauges when I connect them?

 

could it be that the compressor itself is simply bad/ going bad (no cold air at all, loud rattling)

 

TIA

[Txakura]

Wow, lot of views, no posts. I was able to get it to take a charge of about 20 oz of R12 and as I was charging it the compressor shut up. It still rattled a bit on the way home, but it was making cold air.

 

I suppose the PO probably ran it low and kept running it until it didnt work at all, or it all bled out through osmosis.

 

Mainly works now, it's too bad we cant be grandfathered and still service those without the conversion.

[danzick]

personally, i think you should have converted. all the newer vehicles comes stock with the newer stuff you listed. i bought the"conversion kit" and it consisted of a couple dollar fitting that mounted on the old valve, and one of the 4 oz bottles of oil, and like 1 or 2 bottles of refrigerant. very cheap, and the ac like freezes my arms. i have to adjust the hot cold knob.

[eulogious]

personally, i think you should have converted. all the newer vehicles comes stock with the newer stuff you listed. i bought the"conversion kit" and it consisted of a couple dollar fitting that mounted on the old valve, and one of the 4 oz bottles of oil, and like 1 or 2 bottles of refrigerant. very cheap, and the ac like freezes my arms. i have to adjust the hot cold knob.

 

Totally not the way to convert, BTW. You should evac the system, replace the drier, and suck the system down before retrofitting at the minimum. There a several threads on here that explain how to do it correctly.

 

Glad yours works, but don't be too surprised if you run into problems later down the road.

 

Staying with r12 is great if you have access to r12 and really the only way to go. I would not have changed either if I had access to some r12. r12 is colder and works great, no need to replace it if you don't need to. If it ain't broke, don't fix it

[danzick]

if r12 is better why do all the new vehicles come stock with the 13? and ive done the convert to the 13 on 3 vehicles now, and havent had one problem. and its all about convenience. going to the parts store and getting the stuff is easy when you just put the 13 in it.

[eulogious]

if r12 is better why do all the new vehicles come stock with the 13?

 

Really? You don't know why they stopped using r12? The EPA says you can't use r12 anymore, that's why. It has nothing to do with it's ability as a refrigerant. r134a is NOT a superior refrigerant. It's better for the environment, but worse for cooling, compared to r12. r12 is a better refrigerant.

 

r134a doesn't dissipate heat as well as r12, so most systems that have been converted to r134a will not cool as well as r12 because the condenser was designed for r12, not r134a, so therefore it will not dissipate as much heat as a new car will that was designed with a bigger condenser for r134a. This is really the only "downside" to doing a conversion, and it's really not an issue at all.

 

and ive done the convert to the 13 on 3 vehicles now, and havent had one problem. and its all about convenience. going to the parts store and getting the stuff is easy when you just put the 13 in it.

 

When did I mention that converting was bad? I converted my r12 system to r134a just a few weeks ago the proper way, and I don't plan on having any issues what so ever. What I said was that the way you wrote is NOT the proper way to do a conversion, and by doing it the way you wrote will most likely lead to problems down the road. Not that the conversion was a bad idea. A conversion done properly will be just as reliable as the r12. But you missed several key steps in your mention of a "conversion", so I just wanted anyone else that reads this to know that what you did was not the proper way, because it's not. That's all.

 

If I had access to r12, there is no way I would converted my system. That's silly. If I could get it for free, or for the same price as r134a or a little more, without having to go to the store, why would I not use it and not worry about converting? It's silly to say to convert when you have all the stuff to top of your current system at your disposal.

 

If you don't have access to r12, then ya, convert. Otherwise, like I said earlier, if it ain't broke, don't' fix it.

[nipper]

If you can even find R12, make it last as long as possible R134 is an god coolant in a system built for it (larger) and an OK one for a retrofit.

 

Start over from square one here. Us a recycling/vacume pump (by law you have to especially if there is a shop involved, stiff scary fine if not used). The compressor can be rattling due to contomination, or self destruction. The pressure gauges wil really tell you all you need to know.

 

http://www.aircondition.com/tech/questions/82/

 

http://www.aa1car.com/library/ac98.htm