R-12 in R-134 conversion? - Noisy compressor

[torchroadster]

I had a leak develop in my 93 Explorer. I quickly found and repaired the leak, pumped down the system and refilled with R-12. But just as I was adding the last can my compressor started making noises - it quickly got worse and I shut it off. It is blowing cold air but not as cold as it should be.

I've read that the R-12 and R-134 oils are not compatible and I'm wondering if someone had switched this over to R-134 but didn't change the fittings or put on a sticker? If I put R-12 in a converted system would it cause a compressor failure like this? Any other ideas?

Further info....today I checked it again and the bad noise was gone from the compressor, however it was still noisy. I added another can of freon and it seems better now. The noise is still there but not as bad. The low pressure will cut it out if I hold the engine steady at around 3000 rpm, anything less and it's solid on.

 

[BrooklynBay]

Welcome to this forum! R12 is not compatible with R134A. Where did you get R12? I haven't seen it being sold in many years. It was $50 for a small can the last time I saw it in a store. Evacuate the entire system before you kill the compressor. Use the proper oil, and freon without mixing them.

 

[torchroadster]

Brooklyn thanks for the reply - I've had my own personal stash of R-12 for many years. Like I said I'm not sure it was converted to R-134 I'm just guessing. I think it's pretty unlikely someone would convert it without changing the fittings etc. but you never know.

I edited my first post with an update - it doesn't sound nearly as bad now. Hard to describe but sounds more like louder than normal pumping noises - not like it's about to tear itself apart. Pretty strange.....

 

[Glacier991]

When you recharged it, what did you do regarding oil? What was the nature of the leak? slow over time, or catastrophic? You might try adding a can of oil charge...for R-12 systems.... becoming rare.

And Brooklyn... you should see what a full jug of R-12 is going for these days. I thought it was pricey when I paid $600.

(Oh and for a fun little story.... I was out for a walk with my girlfriend a few years ago and there was a pile of stuff sitting out by the end of some guy's driveway... saying FREE. It was mostly useless garage sale kinda shjt...EXCEPT.... there were half a dozen or so cans of R-12 sitting there. NOT FOR LONG. Even though I was half a mile from home, we carried those cans home and she could not help but think I had gone mad, I laughed all the way home!) And yeah BB, it was HER dishwasher too.

 

[torchroadster]

Thanks Glacier - when I recharged it I didn't add any oil. The leak was slow over time - it was a leaky schrader valve. I was kind of thinking the same thing about looking for an oil charge - don't know if they still exist.

 

[Glacier991]

I can send ya one.... 2 oz in R-12... does $10 sound fair?

Or I can loan ya an oil injector.

 

[BrooklynBay]

That sounds like an excellent deal on R-12. Do they even sell it anymore? Somebody once told me that there are places which sell it, but they won't give it to you unless you have some sort of commercial refrigeration repair license. I don't know if this is true or not. Figuring how much a few ounces were when it got banned (at $50 for a small can), I would assume the same amount today would cost several times more (probably about the same price as a few ounces of drugs)!

 

[Brock94]

I thought the price of R-12 is going down now that there are fewer and fewer cars out there that use it. Just checked ebay and there's a 30lb DuPont jug at $350, up in 6 hours with no bids. That's a lot, but not nearly what it used to be.

 

[lifeguard379]

hay glacier. how many cans did you get? I'm in sac and need to fix my ac but don't have the money to convert it. let me know what you would like for some of it.

 

[Glacier991]

I don't have any cans anymore, but have a a jug of it for my use.

And BB it does require a license to buy R-12, which I have.

 

[BrooklynBay]

How do you go about obtaining a license? Are the laws different in each state?

 

[torchroadster]

I can send ya one.... 2 oz in R-12... does $10 sound fair?

Or I can loan ya an oil injector.

Thanks Glacier - that's very generous. I"m going to sit tight for now since it seems to be doing fine.

 

[Glacier991]

It is a federal license.... you can take the course online and the exam.

 

[Brock94]

Yeah, you can get the license online from a company called Mainstream Engineering (google them). You can download the study book for free and then pay something like $25 to take the test when you are ready. If you pass, you get an "electronic certificate" that you can print out right away followed by a wallet sized certificate in the mail.

It's really not that hard, I spent about an hour with the study book and only missed one question on the test. You want to take 609 Certification test which is for MVAC.

 

[BrooklynBay]

How long is it good for? Does it have to be renewed after a certain amount of time?

 

[Glacier991]

Nope. Not that I am aware of. It is not good for HOME stationary AC though, just mobile AC.

 

[scucci]

This is the mainstream engineering link.
http://www.epatest.com/

I got mine in 1996 - it was $19.95 at the time. It is good for life. The automotive license is section 609. It is an open book test. very easy after reading the online manual.

Scucci

 

[BrooklynBay]

Here's the link for the online section 609 study manual: http://www.epatest.com/609/manual/manual.jsp

 

[Brock94]

Nope. Not that I am aware of. It is not good for HOME stationary AC though, just mobile AC.

Right, it enables you to buy refrigerants used for mobile applications only, like R-12. You need a 608 cert to buy R-22 which is usually used in home A/C. There are several "levels" of 608 cert, the lowest being Level I which is for small appliances. Only the lowest is available online, but I think that will allow you to buy R-22, even though it will not permit you to work on a central A/C system for compensation (but if you just want to buy R-22 to fix your own home system, who cares).