A/C question

[michael]

I noticed that R-12 is available on ebay, how hard is it to recharge your own system without an r-134 conversion? I hear you have to vacuum out the old stuff, can this be done by the backyard mechanic?

I thought all the SVX HVAC systems were R134a... My 93 is...



But... all R12 should be gone, and you should use the R134a 'conversion oil' (supposed to mix readily with the R12 oil, and help seals)... I did this on my 89 Saab, a 89 F150, and a 87 Volvo, but I had to replace some seals anyway on all three due to leaks. And yes, if the system had been exposed to the atmosphere, you should replace the dryer AND vacuum the system to remove any water/humidity in the system. The vacuum lowers the boiling point of any water in the system, thus vaporizing it and hopefully removing it. Leave the vac on for a while, I do for 30-40 mins. I've had ZERO problems on those vehicles with that method.

[lee]

Originally posted by The Deviant
I thought all the SVX HVAC systems were R134a... My 93 is...



But... all R12 should be gone, and you should use the R134a 'conversion oil' (supposed to mix readily with the R12 oil, and help seals)... I did this on my 89 Saab, a 89 F150, and a 87 Volvo, but I had to replace some seals anyway on all three due to leaks. And yes, if the system had been exposed to the atmosphere, you should replace the dryer AND vacuum the system to remove any water/humidity in the system. The vacuum lowers the boiling point of any water in the system, thus vaporizing it and hopefully removing it. Leave the vac on for a while, I do for 30-40 mins. I've had ZERO problems on those vehicles with that method.

92 were OEMed with R12.

Vacuum pumping the system not only removes the water, but also is a step in insuring the system has an effective seal before pumping freon R-12 or 134 or whatever, back into the lines.

[thundering02]

Most will have been converted by now mine was just converted this summer. No you don't have to drain the old stuff unless your converting (or fixing) and as long as you have the gauge hookup set then yes this can be done in the driveway. Also R-12 is getting rarer and more expensive since it can no longer be legally produced, but is still quite legal to use and have.

[michael]

Can somebody tell me how to do a r12 recharge mine died about a year ago so I'm assuming the freon just lost it's mojo I don't think I have any leaks. How much stuff do I have to get? and what equipment at what cost? If it lasted 12 years I don't see why I should have to convert if I can get another 12 with a recharge.

[lee]

Originally posted by michael
Can somebody tell me how to do a r12 recharge mine died about a year ago so I'm assuming the freon just lost it's mojo I don't think I have any leaks. How much stuff do I have to get? and what equipment at what cost? If it lasted 12 years I don't see why I should have to convert if I can get another 12 with a recharge.

Unless you can find your way to Mexico, or find someone with a stash (that they're willing to part with) you won't find R12 at any store selling at retail. That's why most people switch to 134.

that said, freon doesn't lose its effectiveness like I think you're suggesting, it's just a gas that gets compressed, cooled, then expands to cool more, just to start the process all over again.

[michael]

Unless you can find your way to Mexico, or find someone with a stash (that they're willing to part with) you won't find R12 at any store selling at retail.

See first post

[lee]

Originally posted by michael
Unless you can find your way to Mexico, or find someone with a stash (that they're willing to part with) you won't find R12 at any store selling at retail.

See first post

sorry, I'm old and can't retain info for long....in which case it works exactly like 134 except for the different connectors. You should be able to get a charging hose at any good auto parts house.

[michael]

How many cans do I have to buy?

[lee]

Originally posted by michael
How many cans do I have to buy?

the answer is "it depends". If you think there are no leaks, yet the system is empty, look on the plaque that's on the hood (or maybe by the radiator - somwhere prominant (by law)), it will tell how many ounces.