I finally had time to check my system this weekend, and I have 0 pressure in the system. The compressor engages if I jump the pressure interlock, so that's good. Since there's nothing in the system, I figure I should take this oportunity to replace the Receiver-Drier. Is there anything else that I should replace on the first go-around? I assume I'll need to evacuate the system when it's back together again. Lastly, where can I find R12 for the best price? The Costco that I used to go to had a ton of it, but the one I go to now does not. Any suggestions?

Thanks.

Is this a good unit?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2479608936&category=43998

For the money, it seems like it would do the job for me. I have a large air compressor that should provide more than enough CFM and pressure to run it. For $14, I figure if it doesn't work, I not out too much.

I think you saw R-22 at Costco.... It would have been several years since they would have carried R-12.

For seldom used vacuum pumps, most Autozone's have one on their loaner tool program. Just ask politely....

Michael

No, it was definately R-12. There was a notice indicating that they could only sell it to licensed technicians, etc. etc. Might have been a one time deal. Ah, well.

I picked up one of the venturi pumps for $10. We'll see how it works. I hate borrowing tools. :)

Thanks.

Where do you live?

Just tell me the Costco SKU # and I'll get my local COSTCO to find it in the computer....


I haven't seen R-12 in a store in 10 years openly displayed. How much was it? A 30# container of R-12 is going for about $300.


Michael

The Costco that had it was in Holbrook, NY on Long Island. They had the small (1 lb, I think) cans. I don't remember the price, but it was pretty cheap. The Costco near me now (Springfield, MA) gave me a blank stare when I asked about R12. I'll probably buy some off of eBay or something like that. Thanks, though.

Is fastlane parts site down for anyone else besides me?

Oils.

I converted my system to R134A in the 82 300TD. BUT I installed A paralell flow condensor. I am experimenting with the R134a temperatures and application. I may evecuate the R134A and install R12 if the R134a conversion cannot keep up with Texas heat.
So If your going to go to the trouble of flushing and replaceing Orings for the conversion Install Synthetic oil.

http://store.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=41-50062-2

It is compatable with both R134a and R12. So my conversion back to R12, if I decide to do it will only require evacuateing the system and installing R12. No other work.

Use the BAV Auto 100 oil. And your system is capable of using EITHER R12 or R134a, Not both at the same time!!!!!

Gauges.
I bought a set fo R12 and R134a guages from Harbor Freight. $50 each. Iknow there cheap but they seem to be working fine.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=2435

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=1504

Vacuum pump.
HF also sells the Venturi pump for $10

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=3952

It will work OK. But a larger pump will make your system work better.

Dave

MP39 Freon(?)
 

I read, somewhere, that this is a direct replacement for R-12. Anyone know for sure?

Jim

This has been one of the best threads for A/C questions I have come across.

Off on my daily trek to Pick-A-Part to look for an upgrade condensor. I'm not quite sure what to look for, but I suspect that parallel flow is probably self explanitory. There were some fresh European carcases coming in yesterday. Anybody need anything?

I havew read that the venturi pumps don't work well enough for A/C systems. I am waiting for results report. I was thinking about drawing as much vacuum as I could, then putting in dry air (nitrogen/helium mix from the mig welder) and drawing vacuum again.

The idea of using an A/C compressor for a vacuum pump is sharp. I had all kinds of home brew contraptions in mind, but this one looks simple. Does the polarity on the clutch matter? I would think since it is probably just an electro magnet, it probably wouldn't. It looks like the fittings on the pipes on the hoses coming off the compressor might be pipe thread. I will have to plumb the low side of the makeshift vacuum pump to the schraeder valve on the car.

Thanks for the suggestion on the o-ring kit from AutoZone.

What about oil for the new system? I see compressor oil (mineral oil) at Grainger for about $3.50 a quart. Is this what I want for an R12 system? It doesn't specify A/C service in the online catalog.

Finally where is the evaporator and how do I get at it? I am as far as the expansion valve and getting those boxes apart is a mystery. I would like to look at it and clean it as necessary. I would bet the airflow is crap. The first quart of flush (mineral spirits) came out the color of rusty water. That was dumped and the remaining 3 quarts were run through several times. The first flush of denatured alcohol was aslo a little brown. I used an RV water pump and a couple of buckets to pass flush through the evaporator.