A/C recharge help please Options

[SwissFerdi]

Hi guys. A while ago when I replaced the alt belt, I accidentally undid the a/c line underneath (stupid, but this is how we learn). I got a nice blast of refrigerant and I assume the whole system is now voided. Will I have to take this to a professional for a machine job or will a few cans of recharge stuff take care of it? Should I pressure check first to gauge?

Thanks in advance!

This post has been edited by SwissFerdi: Jun 14, 2016 - 11:35 AM

[richee3]

Hope you didn't breathe any of it! Unfortunately you'll need to take it to a shop to have the system vacuumed and pressure tested before recharging. I've seen some shops like Midas run a/c specials for like $50 and they claim they'll vacuum and recharge the system but in reality all they probably is top the system off.

[Box]

You can buy a gauge set, vacuum pump, and refrigerant to do it yourself properly or take it to a reputable shop/dealer, the DIY top off cans from the parts store really aren't the way to do it. Really something like Richee mentioned will probably be your cheapest and easiest solution.

[Bitter]

By the time you buy all the stuff to DIY you'll have paid as much as to have someone do it for you, so if you're going to be doing it regularly then yes get a DIY setup going, otherwise pay someone else. System needs to be pulled to vacuum then recharged, otherwise air and water in the system will make it work incorrectly. It's a really wise idea to replace the receiver dryer now because it's been exposed to moist air and may no longer function correctly. Make sure they check pressures not just at idle but also at 2500 RPM to make sure the high side is staying in normal bounds, an excessively high high side with proper charge level can indicate some issues like you're missing 1/2 the fins on your condenser! PS, good time to check to see if you're missing half the fins on the condenser and replace it if you are. I replaced the one on my 7G and my AC blows ice cold like a brand new car again.

[Spider77]

The drier should be replaced whenever the system is opened up (as in component replacement). If your going to do this on a regular basis probably wouldn't hurt to be certified.

[SwissFerdi]

Thanks for the advice guys, it is really appreciated! Still a great community here.

Replace the receiver drier, got it. I was not planning on doing this often, having said that, the Miata A/C doesn't blow cold anymore either but I was under the impression that the aforementioned A/C-in-a-can top off probably takes care of that, unless there is a leak.

I'll look into DIY options for the sake of it but I think I might pony up for a pro on this one. Thanks again everyone.

This post has been edited by SwissFerdi: Jun 14, 2016 - 7:35 PM

[VavAlephVav]

here's my lengthy explanation that basically concludes what the other guys have already told you.
In the long run it's cheaper to take it to a shop, yet there are many who still don't do it right.

http://www.6gc.net/forums/index.php?showto...ir+conditioning

Although If you are handy with these kinds of things you may be able to get a set of gauges and a vacuum pump from a pawn shop or borrow them from a friend.

Good luck.

This post has been edited by VavAlephVav: Jun 14, 2016 - 8:57 PM

[SwissFerdi]

Wow, that is a healthy writeup! I think considering the specialized nature of the tools, fittings etc., I'll probably take it somewhere. There's a local place that did a good alignment job, and that's the only thing the car's been to a shop for in 8 years. Thank you for creating that how-to.

[trdproven]

typically when you open up a system that's especially been working for a quite some time needs the drier replaced.

you can buy a gauge, vacuum, a refrigerant and do it yourself as mentioned above. its really specialized tools so you either get it done at the shop and that's it, or you end up getting into it and buying the tools hoping or expecting you make use of the tools. but if you like diy's then this is for you especially if you're the type for the learning and skillset experience, one good job should pay for the tools itself on the first major repair given they charge appr. 500 bucks where I'm at.

[VavAlephVav]

Depending on what your local pawn shop may have you can pick up a set of gages for $50, and maybe find a vacuum pump for $100, and I have a thermometer built into the electric multi-meter I use for electrical testing, and that's all I need just to charge up a system. Assuming it's already empty then all you really need to do is pull a vacuum and let that pull the R134a into it. After replacing the liquid line filter/dryer as TRD said. Proper procedure is to replace that anytime the sealed system is opened.

[SwissFerdi]

Thanks for the help guys. I'm a little intimidated to DIY after seeing the write-up, but I will gauge (ha!) how the Miata goes and then go from there. It seems the be just low so a simple charge in a can should do it. I'm a little concerned on the Celica about temperature monitoring on the pipes.

[Bitter]

I did a DIY recharge when I replaced my condenser at home on the 7G, it also contains the dryer though. $50 vacuum pump, borrowed cheap gauge set from my friend, can tap, and a 12oz can of 134a I grabbed on sale. I got enough charge to run the system to make sure it worked then topped it up at the shop. The biggest trick is to put the 134a can in HOT HOT water so the pressure rises and you can get more of the can in there, I had nothing but vapor in the can and not even very much of that. If you charge that way you can get close to a correct charge and verify the system is working, cooling, and not leaking. Charging by low/high pressure is fairly close to charging by weight, that's how my Celica is charged right now since the scale is a little off at work.

[VavAlephVav]

Yes, very good tip about heating up the 134 can to raise the pressure in the can. If I were charging from my 30 pound jug of R134a I would bring it in as a liquid and then barely crack the low-side valve to meter it in so that it flashes to a vapor as it passes through the valve. But this technique is not for beginners .

I haven't told you guys that just recently I got a summer internship with a company that custom makes really large commercial air conditioning machines. I am going to be a design engineer for them after I graduate next year, and I get to spend the summer working my way around each station in the factory.

I am already having this conversation with myself:
Mk4 Supra, but the Mr2 is better for a track car, and the MrS would be nice with a hardtop kit, and a V6, why can't I get a supercharger for that?
Maybe the Supra is the DD unless I get a gt4 rear-end and make my Celica awd then maybe that would be DD...

[Bitter]

How about you stay a year at the job before you jizz all over your dream cars?

[trdproven]

If you don't know how to read gauges when you charge, find a refill that matches up exact to spec like 18oz for example, and you can just charge it one shot, if not you can get one bigger and just weigh it first and deduct the 18oz from it and stop the charge.

Make sure you pressure test it, it should be somewhere close to the -25 or -30 something like that, should be near the last line, and then close your ports and leave it for about 30-45 minutes and see if it moves up, if it does, its leaking somewhere.

This post has been edited by trdproven: Jun 27, 2016 - 4:49 PM

[VavAlephVav]

And did anybody mention compressor oil?
They sell little 8oz cans of the oil for the compressor, you just charge it in the hose like the refrigerant.
Basically, if the compressor it making a bunch of noise then it needs a little more oil. I think it would need 8oz if it were completely empty, and there is generally a couple ounces still left in the compressor even if you release all of the refrigerant charge.

[trdproven]

ya you can double-check the oil, but if you're changing the compressor out, you can buy one preoiled like a denso brand.