Charging the A/C

[j.fro]

Has anyone here DIY'd their A/C?
Mine is only marginally cool, so I suspect it needs a bit of refridgerant.
If it's not a DIY job, what might I expect to pay?

[MNBoxster]

Hi,

It's doable as a DIY project, but generally, best left to the pros.

To do it properly, you need to drain the system, evacuate it using a vacuum pump (which boils off any remaining moisture and Oil), add a specidic amount of a specific Oil (ND 8 - 6.6 ± 0.5 oz.) and then add the refrigerant (R134a - 850 g (30.0 oz.)).

In theory, you should never need a recharge, but in practice, because there are so many joints in the system, an 'O' ring will usually dry up and allow some of the refrigerant gas to escape. A Shop can identify the leak and replace the 'O' ring(s).

Also, despite DIY kits being available commercially, US Law (EPA) requires that anyone servicing an AC system be certified in completing an EPA recycling course (available here - http://www.epatest.com/608/ ). I have taken this test and can do a system. I own a vacuum pump, but lack the required recovery equipment, so I just leave it to the pros.

R134a was developed as an alternative to R12 (Freon) which was found to be Ozone depleting. Subsequently, it was found that R134a while not directly Ozone depleting, will combine with Sunlight and other atmospheric releases to form compounds which do deplete the Ozone layer and so should not be free-vented. A Shop will have the proper recovery equipment (assuming any of this matters to you). Good Luck!...

Happy Motoring!... Jim'99

[porschedude]

I would put half a can of R134 and see if AC cools down. If AC blows warm again in a week, then you have a leak. You only need to deplete the system and vacuum if there is a leak and you need to repair the leak. It is not a good idea to merely release the R134 to the atmosphere. If you have not charged the AC system in 4-5 years, then you are probably a little low on R134 and that is quite normal. You can purchase a can of R134 anywhere without a license but not for R12.

[MNBoxster]

Originally Posted by porschedude

I would put half a can of R134 and see if AC cools down. If AC blows warm again in a week, then you have a leak. You only need to deplete the system and vacuum if there is a leak and you need to repair the leak. It is not a good idea to merely release the R134 to the atmosphere. If you have not charged the AC system in 4-5 years, then you are probably a little low on R134 and that is quite normal. You can purchase a can of R134 anywhere without a license but not for R12.

Hi,

If he needs to add refrigerant, then he has a leak. Also, adding only refrigerant does not ensure a proper level of compressor Oil and this will cause premature compressor failure.

You can buy R134a, but according to Federal EPA Law, it's still unlawful to service the system w/o certification or a Recovery Machine - a Catch-22, I agree, but there it is...

Happy Motoring!... Jim'99

[deliriousga]

Check it before adding anything. If you overcharge it, you can damage the system. Like Jim said, you need to take the course and get the certification. If you don't evacuate any refridgerant, you're not required to have a vacuum so you can check and fill. The certification is only about $25 and it took less than an hour to complete. If it is low, fill it then take it somewhere to find the leak.

I'm taking one of my cars to a local shop to evacuate the system then I will go through and replace all of the o-rings and refill it. It's not difficult, just time consuming.

Btw, if you take it to a shop and they tell you they are not allowed to top it off because they are required to fix the problem first, report them. It's a lie shops use to make extra $$ and it's a violation of their certification.

[Dr. Kill]

Originally Posted by MNBoxster

Hi,

It's doable as a DIY project, but generally, best left to the pros.

To do it properly, you need to drain the system, evacuate it using a vacuum pump (which boils off any remaining moisture and Oil), add a specidic amount of a specific Oil (ND 8 - 6.6 ± 0.5 oz.) and then add the refrigerant (R134a - 850 g (30.0 oz.)).

In theory, you should never need a recharge, but in practice, because there are so many joints in the system, an 'O' ring will usually dry up and allow some of the refrigerant gas to escape. A Shop can identify the leak and replace the 'O' ring(s).

Also, despite DIY kits being available commercially, US Law (EPA) requires that anyone servicing an AC system be certified in completing an EPA recycling course (available here - http://www.epatest.com/608/ ). I have taken this test and can do a system. I own a vacuum pump, but lack the required recovery equipment, so I just leave it to the pros.

R134a was developed as an alternative to R12 (Freon) which was found to be Ozone depleting. Subsequently, it was found that R134a while not directly Ozone depleting, will combine with Sunlight and other atmospheric releases to form compounds which do deplete the Ozone layer and so should not be free-vented. A Shop will have the proper recovery equipment (assuming any of this matters to you). Good Luck!...

Happy Motoring!... Jim'99

Jim you are a walking encyclopedia - very helpful to many of us.

I replied yesterday about charging my system with some Durametric codes and someone removed it.


Anyhows, I ran into a 30 code, and 1457, that I haven't hunted down yet. Since I mistakenly thought the 1457 "low something.." In ended up putting 1/2 can of 134a into it.

It did seem a little bit cooler. Even without a guage, I highly doubt I overcharged it, after 4 years it's bound to lose a little. I'll get to the codes later this summer...


RE: Theorhetically speaking...


In the real world, I've gotten away with adding a can here and there every summer in many of my cars over the years. A/C systems leak, and it's a fact of life. If the feds were to dock everyone whos had an out of spec. car we'd all be broke. Or maybe we'd just all be Japanese.