Recharging A/C - better left to the professionals?

[lairdwd]

I'm getting conflicting views if recharging an A/C is something for the lightweight DIY'er. I did my own for the first time on my 17 year old altima. For 3 months it worked great, then the compressor died and I don't know if it was age related or if I screwed up the recharge..

The recharge kits they sell in the store make me nervous .. For example, do they have the right oil? (PAG vs. Esther) with the right mix?

I think this is one job I'm going to wait for a coupon and bring it in to the dealer for my wife's car. Seems like A/C is something that needs to be flushed and done right, and that the DIY cans they sell, you're really playing with fire.

 

[Herz]

I dont have the courage to do it myself in my cars.

 

[Billbert]

AZ sells a DVD that is pretty informative about A/C repairs and recharges. They also rent/loan professional type A/C gauge sets so it can be done properly. A simple recharge is easy, but you should monitor high side pressures.

 

[Quest]

First and foremost: do you know if your refrigerant type is R134A or R12? If it's R12, your option is next to nil (either go down south X the border to Mexico and find someone to help you recharge your system, or (b) retrofit it with R134A retro kit).

IMHO no matter what you do: if you aren't sure, don't touch it for the likeliness of damaging your system is high and the repair will be really costly (be it R12 or R134A systems).

Q.

 

[fdcg27]

I think you are better off giving someone the hundred or so dollars it will cost to fully evacuate the system, put it under vacuum for awhile, and then properly fill it, using the right lube.
Modern AC systems don't seem to need much maintenance, as long as the compressor is run regularly.
The AC in our two twelve year olds works great, and has never needed any service, including any recharge.

 

[JHZR2]

It is pretty easy to do, and if you know the history/soundness of the system (e.g. No r12 topped with 134a), it is pretty straightforward. A set of decent gauges does help, most of the kits and charging handles, IMO, are so cheap and lousy that you do risk leakage, release, etc.

The main requirement IMO is to have a gauge, but for a cheapo system, a simple hand-operated valve is the best, forget the trigger type devices.

It is very doable, and pretty easy. It really is best to do a static test on low and high side, then watch both as you fill.

 

[lairdwd]

It is R134a, and I'm familiar with the DIY kit with pressure gauges.

However, I've read comments from A/C techs that the A/C system is very finicky and not very forgiving. I can never get a good answer if those DIY kits are suitable for my honda accord's compressor - which takes PAG 46 oil. I know there are two types of recharge kits - one with PAG and one with Esther. I doubt either has the right mix specific to my compressor.

I think I will pay the $100 and have the entire system evacuated and done right. That's one expensive repair should the system get toasted and it only gets recharged every 5-10 years or so anyway.

 

[djb]

You don't need to leave it to the professionals, but it's not as simple as an oil change. You need some specialized equipment -- at least a "gauge set" (valve body with hoses and gauges) and a vacuum pump.

Did you pull a vacuum on the system before adding the refrigerant? If not, that very likely caused the compressor failure.

Most of the kits never mention that they are pretty much useless for their listed purpose. There is almost no circumstance where they are sufficient solution, let alone the correct fix.

You really need a gauge set, particularly the valves on the gauge set, to avoid letting air back into the system between pulling the vacuum and refilling.

The vacuum pump can be as sleazy as a venturi pump ($10-$15) combined with a big air compressor. But that's marginal -- a piston vacuum pump ($85-$300 for basic models) works much better.

 

[beast3300]

Well, without recovery the system you won't know how much refrigerant the system had. Also pulling it out also tells you the system is close to 0 lbs of refrigerant. And you do want the system placed under "deep vacuum" to boil the moisture in the system to get it out (I usually do 45mins to an hour.) This will give you a much better performing AC system.

Machines such as RTI machines will only take out excessive oil that is in the system. 9 times out of 10 you should have to add AC oil unless you replace the AC compressor. Recover, deep vacuum, recharge and go.

 

[Steve S]

Even though it is really easy to add refrigerant. The proper way would be to check for leaks with a sniffer. Then repair the leak evacuate the moisture from the reciever dryer and the rest of the system, then recharge and test system.

 

[mechtech2]

Having it evacuated will not change the oil in the system.
Who knows what mix you have in there now? And who knows what is wrong with any parts? How about particulate matter in the lines if something did fail internally?

In general, DIYs can top up their systems with R134a easily and successfully. Don't overcharge!
But with problems known and unknown, who can tell?
To do this right by a pro will be expensive. They will have to dig deep to be able to guaranty it.

 

[demarpaint]

It is fairly easy to do, once you know how, and have the proper equipment. I would recommend doing it when the temps are warm or in a heated garage for best results.

 

[wtd]

Like other have said, if you have the right equipment and a little know how its not too hard. Buying the equipment the first time is a little expensive but after that its not bad. I've fixed/recharged six vehicles in the three and a half years since I've learned how to repair AC systems on my own. I did some research online and went to some online forums and figured out what I needed to do and what to buy.

Don't use the kits the autoparts stores sell. Don't use sealers as they can ruin your system. A good set of gauges and a good vacuumn pump is essential.

Wayne

 

[JHZR2]

Originally Posted By: lairdwd
It is R134a, and I'm familiar with the DIY kit with pressure gauges.

However, I've read comments from A/C techs that the A/C system is very finicky and not very forgiving. I can never get a good answer if those DIY kits are suitable for my honda accord's compressor - which takes PAG 46 oil. I know there are two types of recharge kits - one with PAG and one with Esther. I doubt either has the right mix specific to my compressor.

I think I will pay the $100 and have the entire system evacuated and done right. That's one expensive repair should the system get toasted and it only gets recharged every 5-10 years or so anyway.


ok, let's say that your system still has useful pressure, so no chance of moisture, but is just low...

Reading static pressure will indicate if there is one or two phases in there, then charging with a gauge will get you close. You're not feeding from a 30# container, so chance of overfilling is not that terrible.

Evacuation isn't necessary if pressure didn't run too low and the system was functional... And I don't see why oil is any sort of a question... You would buy cans of plain r134a, not the kind that has any oil mixed in.

If I was worried about oil, I wouldn't just have th system evacuated, but would open the system up, replace the r/d, and use solvent to clean anything out.

 

[Kestas]

I taught myself automotive a/c repair by spending many hours reading on the automotive air conditioning boards. This knowledge together with a few tools (specifically, vacuum pump and gauges) will make you a good DIY a/c repairman. It is one of the more financially rewarding DIY projects you can do.

If you're willing to learn automotive a/c and buy the proper tools (they'll pay for themselves with the first repair), then I see no reason to go to a professional.

 

[artbuc]

Originally Posted By: Kestas
I taught myself automotive a/c repair by spending many hours reading on the automotive air conditioning boards. This knowledge together with a few tools (specifically, vacuum pump and gauges) will make you a good DIY a/c repairman. It is one of the more financially rewarding DIY projects you can do.

If you're willing to learn automotive a/c and buy the proper tools (they'll pay for themselves with the first repair), then I see no reason to go to a professional.


I totally agree with Kestas. I bought a 2 stage vac pump from HB on sale for less than $75 and it worked great. Also bought a cheap set of gages. Make sure you do the research (general auto A/C plus specifics for your vehicle). You can buy cans of 134a from Kmart for a buck or so. I had to replace a condenser so I needed to make sure I added the right amount and type of oil. Everything works great now. As posted earlier, you don't have to evacuate if you already have positive system pressure.

 

[SevenBizzos]

Three years ago I charged my A/C with a bottle and know idea what I was doing. Since then the A/C has worked great and there's been no issues. Not bad for a 1994 that's never had any documented A/C service...