Recharging AC

[MysticGold04]

in my Highlander.. just out of curiosity.. If I can't see bubbles in the "looking glass" should I/is it advisable to recharge? I notice its not getting quite as cold as it once did. A local shop charges $29 for the service and $30 per lb. of R-134. ??

I see those cans of Synthetic stuff with the hose at Autozone/OReilleys for about $28 or so...

 

[97prizm]

I've been told by many not to go the DIY A/C route from a parts chain. Although... I did this a couple of years ago and used the big blue "Artic Freeze" can and my geo prizm seems to have much colder a/c now. It's been two or three years and still works great. If your car is fairly new I'd take it to a trusted mechanic.

 

[scurvy]

If your local shop only charges $30 for service and per pound of R134a by all means let them evacuate, vacuum & recharge your system.

It will likely be done right and you'll have the proper mass of refrigerant in the system when they're done. If you DIY only with the gauge-top can you have a very incomplete picture of what's happening in your AC system.

I've used the AutoZone cans before when my Volvo 850's compressor was cycling on and off - added just enough refrigerant to keep it from cycling on a very hot day and no more. But if yours is still working OK but 'seems not as cold' you're better off having the system serviced instead of going DIY.

 

[DrDusty86]

I just did my car, which has a leaking schrader valve. I had a ford dealer do it. He also did a complete system check. They charged me $20 per pound. Overall I'm VERY happy I let a pro do it. It saved a lot of headaches. Should be good for another 13 years..I hope

 

[440Magnum]

A "looking glass" in an R-134a system? Strange.

R-134a frequently has bubbles in the discharge line under normal charge. Its NOT a reliable test of charge state, so virtually all manufacturers deleted the sight glass from factory R-134a systems. It serves no purpose.

 

[Spinall4]

Unless you ready to apnea some time learning and mony buying the right tools, leave ac to the pros.

At the very minimum you would need to buy a set of gauges, a vacum Venturi or real vac pump if you don't have a super big compressor, 2-3 cans of r-134, some r134 with leak dye, a black light kit with the glasses.

If you are DIY ac, the only things that ever should go into an ac system are r134, oil, and the leak detection dye. It seems like all the other stuff like leak sealer, hyper ac booster, all cause more harm than good.

 

[mechtech2]

Originally Posted By: scurvy
If your local shop only charges $30 for service and per pound of R134a by all means let them evacuate, vacuum & recharge your system.

It will likely be done right and you'll have the proper mass of refrigerant in the system when they're done. If you DIY only with the gauge-top can you have a very incomplete picture of what's happening in your AC system.

I've used the AutoZone cans before when my Volvo 850's compressor was cycling on and off - added just enough refrigerant to keep it from cycling on a very hot day and no more. But if yours is still working OK but 'seems not as cold' you're better off having the system serviced instead of going DIY.


Why in the world would they evacuate the system?
They will simply ad refrigerant and kick it out the door.
A sight glass is really rare in new r134a systems.
For $60 or so, I'd let them check out and fill the system, if you are not conversant n AC systems.
Or, do homework on the interweb and charge it yourself . Get a hose/filler that can be reused with other standard cans, BTW. May are 'one shot' deals.

 

[scurvy]

Originally Posted By: mechtech2
Why in the world would they evacuate the system?


To ensure the system isn't leaking and to give them a baseline so they know when the system has a full charge. This isn't rocket science - the system capacity is often on an underhood sticker. If you don't know how much is in the system to begin with, you're only guessing at the appropriate charge.

Evacuating, vacuuming & recharging is the proper way to do it. If the shop won't do that, I wouldn't give them my business.

 

[crazy8]

Originally Posted By: MysticGold04
in my Highlander.. just out of curiosity.. If I can't see bubbles in the "looking glass" should I/is it advisable to recharge? I notice its not getting quite as cold as it once did. A local shop charges $29 for the service and $30 per lb. of R-134. ??

I see those cans of Synthetic stuff with the hose at Autozone/OReilleys for about $28 or so...


Your best bet sounds like your local shop, have them evacuate and recharge the system for the best cooling.

Please, Please never use the DIY cans sold in the stores, this stuff should be illegal, most if not all contain a sealer that will eventally cause a problem in your system.

In the professional repair shop we are required by law to test the freon before recharging a system and if it does not test 100% R134a the system must be evacuated into a special container and be disposed of by a Haz Mat company. In our shop we first test for sealer and then freon quality. If we find sealer or contaminated freon we are done, if we attempt to recover this [censored] it will kill our RRR machine and contaminate every car we service until we find out about the bad [censored] that someone used trying to fix a poor performing a/c system. According to MACS the only recommended proceedure to deal with this problem is to recover the freon into a Haz Mat container and replace the entire A/C system on the car, which is a very expensive repair, We are now finding aprox 25% of the cars that come in for A/C repairs to be contaminated, when I ask the customer how or who did that most will say a freind or neighbor who was trying to help, it turns out to be a very expensive mistake.

 

[bdcardinal]

We have to do this to, so many problems come up from the OTC cans not being 100% R134a

 

[Rock_Hudstone]

Originally Posted By: crazy8
Please, Please never use the DIY cans sold in the stores, this stuff should be illegal, most if not all contain a sealer that will eventally cause a problem in your system.

It would have be someone from San Francisco suggesting another consumer product be made illegal, (by government edict naturally).

Pure hysteria over what is probably a system that merely needs a slight topping off.

 

[Colt45ws]

I only buy the pure stuff in the cans for my car. You can get 100% R134a if you simply read the labels. Generally, its the cheapest stuff too.
I did use some sealer in the Saturn, but I couldnt care any less about that thing. If I decide to try to top it up again though, it is getting 100%. Simply because I dont want sealer going through my nice gauge set.

 

[artbuc]

Originally Posted By: 440Magnum
A "looking glass" in an R-134a system? Strange.

R-134a frequently has bubbles in the discharge line under normal charge. Its NOT a reliable test of charge state, so virtually all manufacturers deleted the sight glass from factory R-134a systems. It serves no purpose.



Can't totally agree with this. My 99 Avalon has a 134a system with a sight glass. The FSM gives detailed descriptions of what the bubble pattern should look like under various conditions. When I had to replace my condenser a few years ago (road rock damage) I carefully weighed in the specified charge and monitored the sight glass to watch the bubble pattern. The FSM was exactly right and the bubble pattern perfectly matched the FSM description at full charge. I believe sight glasses were deleted primarily to reduce cost.

 

[crazy8]

Originally Posted By: Rock_Hudstone
Originally Posted By: crazy8
Please, Please never use the DIY cans sold in the stores, this stuff should be illegal, most if not all contain a sealer that will eventally cause a problem in your system.

It would have be someone from San Francisco suggesting another consumer product be made illegal, (by government edict naturally).

Pure hysteria over what is probably a system that merely needs a slight topping off.


Rock_hudstone, for what it's worth I live 30 miles to close to SF, I actually hate living here, I stay for my wife and kids. I would like see the cans of R134a with sealer in them banned, not plain R134a. I feel that if a system is slightly low and a person is able to buy a can and DIY that is ok.

 

[mechtech2]

Originally Posted By: scurvy
Originally Posted By: mechtech2
Why in the world would they evacuate the system?


To ensure the system isn't leaking and to give them a baseline so they know when the system has a full charge. This isn't rocket science - the system capacity is often on an underhood sticker. If you don't know how much is in the system to begin with, you're only guessing at the appropriate charge.

Evacuating, vacuuming & recharging is the proper way to do it. If the shop won't do that, I wouldn't give them my business.


Nonsense.
Pressure testing or especially an infrared thermometer are great ways to fill a system. With known and controlled conditions, the thermometer method is superb.
Evacuation testing often does not show leaks. Because they may leak under pressure, not vacuum, or visa versa. A sniffer is best for testing for leaks.

 

[Jim Spahr]

Is the All Pro in the black cans at AZ and Advance Auto with the single gauge the R-134 with sealer you are warning about? It sells for about $45.00.

 

[yonyon]

Originally Posted By: 440Magnum
A "looking glass" in an R-134a system? Strange.

R-134a frequently has bubbles in the discharge line under normal charge. Its NOT a reliable test of charge state, so virtually all manufacturers deleted the sight glass from factory R-134a systems. It serves no purpose.



It's a Toyota thing. You wouldn't understand.

 

[Colt45ws]

Originally Posted By: Jim Spahr
Is the All Pro in the black cans at AZ and Advance Auto with the single gauge the R-134 with sealer you are warning about? It sells for about $45.00.

Ive read many cans, and most have a sealer. Read the can carefully. Especially if it touts an additive that 'supercharges' the A/C system. You want the cheap plain R134a.

 

[sleddriver]

I checked out a Dollar General? or Dollar Store? searching for some deals on Regane I heard about and stumbled upon cans of 100% R134a for $7 each

I loaded up as I periodically have to top up the A/C in the sled.

Don't buy anything with 'sealer', 'stop-leak', etc on the label. You can buy a REAL valve with a short hose and fitting at Advance Auto.

 

[crazy8]

Originally Posted By: Jim Spahr
Is the All Pro in the black cans at AZ and Advance Auto with the single gauge the R-134 with sealer you are warning about? It sells for about $45.00.


I don't know that brand so it's hard to say. I have looked at cans being sold and I would say that close to 90% of the DIY cans contain something other than 100% R134a.
I can only offer that you read the contents very carefully and only purchase a can with 100% pure R134a only.