Can I recharge my A/C?

[lothos]

Hey guys.

I have a 1995 STS, almost 14 years old. The air conditioning doesn't work. I am getting no codes for it. When I turn on the AC, it blows hot at first. After a couple minutes it blows cool/cooler, but not cold.

From reading through the posts on here it sounds like the refrigerant might be low, but not low enough to set a code. If I can borrow a nice set of gauges that monitors both high and low ports I'd like to add two 12oz cans of refrigerant. Does it sound like that's all I need to do?

Also, I was at Walmart and found a variety of recharge kits. I've read on here not to use a can with sealant in it, or oil, but what about a can with ring conditioner? I took a picture of a can without any additives, can anyone confirm that it's the one I need?

Thanks for the help guys!

[Ranger]

Use the one with no additives. You might only need one can and can add it with the adapter that comes with the can, although a set of gauges would be better top monitor the pressures.

[BodybyFisher]

I think that AC systems benefit greatly from an evacuate and recharge. Moisture is pulled out of the system and a fresh recharge of freon. You can opt for them to give it an oil charge and dye charge also.

I am not really a fan of using the cans, but maybe if you just need a small amount of freon this would be a quick fix.

[Ranger]

I am not really a fan of using the cans

Why not Mike?

[BodybyFisher]

I am not really a fan of using the cans

Why not Mike?

Well I guess my main reason is because I fell that without proper gages you chance overcharging the system and feel that if it has leaked down its best to exacuate the system get the moisture out, and put the proper amount back in. More is not better. Maybe it is a good bandaid, but I have found that if I take my car in every couple of years to have it evacuated and recharged I can see if I am losing any freon and get any moisture out.

[Texas Jim]

If it is cooling...but just not COLD... it is still pressurized.

How could moisture get in the system if it is still under pressure?

(greater then atmospheric pressure)

Not trying to argue... just asking for (hopefully) my own benifit.

I have manifold guages and have recharged my systems (down thru the years) when they are just a little low, without pulling a vacumn on them.

I do have a vacumn pump

Heck... I still have a couple of cases of R12 out in the shed.

May have another older car that needs it some day.

If the system has been opened for ANY REASON..

THEN I pull vacumn and recharge to spec.

Any enlightenment will be appreciated.

[KHE]

As long as the system still has a partial charge of refrigerant, it is perfectly fine to top it off. I prefer to leak check trhe system that needs a charge and repair the leak if it is a significant leak. A signigicant leak would be a leak that requires recharging every season or sooner.

You can get close by using the manifold gages and charging by pressure but the most accurate method is to recover and weigh the refrigerant and compare that to the system specification.

I use 134a refrigerant in the 30 lb cylinders - it is fine to use the cans but remember that with a manifold gage set, you will have 2 ozs in the hoses and you'll lose 1/2-1 oz every time you change the cans so you need to take that into account when figuring how many cans you will need for the recharge. With a 30 lb cylinder, the cylinder is placed on a scale and the refrigerant gage set is hooked up and the air is burped from the lines. Then the scale is zeroed out and when the system is charged, the exact amount of the charge is read directly from the scale.

[BodybyFisher]

If it is cooling...but just not COLD... it is still pressurized.

How could moisture get in the system if it is still under pressure?

(greater then atmospheric pressure)

Not trying to argue... just asking for (hopefully) my own benifit.

I have manifold guages and have recharged my systems (down thru the years) when they are just a little low, without pulling a vacumn on them.

I do have a vacumn pump

Heck... I still have a couple of cases of R12 out in the shed.

May have another older car that needs it some day.

If the system has been opened for ANY REASON..

THEN I pull vacumn and recharge to spec.

Any enlightenment will be appreciated.

I can be a thick head at times, and I admit that a single can can be a band-aid, but since I have gone to the effort to rebuild my AC, feel that evacuating and recharging with the gages is the optimum method.

A couple of weeks ago we had a member arbitrarily put 2 cans in and his high pressure switch was set off and he was trying to put more in, then Dana where his system would not take a single can. I don't know I tend to be conservative about this and feel at times the arbitrarily adding cans with out the data from the gages can be 'flying blind'. But I suppose it is an alternative

[KHE]

If it is cooling...but just not COLD... it is still pressurized.

How could moisture get in the system if it is still under pressure?

(greater then atmospheric pressure)

Not trying to argue... just asking for (hopefully) my own benifit.

I have manifold guages and have recharged my systems (down thru the years) when they are just a little low, without pulling a vacumn on them.

I do have a vacumn pump

Heck... I still have a couple of cases of R12 out in the shed.

May have another older car that needs it some day.

If the system has been opened for ANY REASON..

THEN I pull vacumn and recharge to spec.

Any enlightenment will be appreciated.

I can be a thick head at times, and I admit that a single can can be a band-aid, but since I have gone to the effort to rebuild my AC, feel that evacuating and recharging with the gages is the optimum method.

A couple of weeks ago we had a member arbitrarily put 2 cans in and his high pressure switch was set off and he was trying to put more in, then Dana where his system would not take a single can. I don't know I tend to be conservative about this and feel at times the arbitrarily adding cans with out the data from the gages can be 'flying blind'. But I suppose it is an alternative

Adding refrigerant by the can without gages can be flying blind but if the system is so low that the vent temp is "warm", there's little harm in adding a can to get the vent temps back in the range. I tend to want to "look for the leak" when I need to add a pound or less refrigerant to a car.

[lothos]

Well I got a can of 134a and borrowed some gauges. I added almost a whole can and got the PSI up close to where it should be. It was easier than I thought it would. When I turned off the car I could hear a hissing noise, that seems to be coming from the tube that goes back to the condenser, down in between the battery and the serpentine belt.

I was thinking of getting a can of 134a with the dye in it to find the leak, but unless there's an O ring or something down there that would be easy and cheap to fix I think I'll give up at this point and concentrate on the ball joint that I have to learn how to fix

[KHE]

Was it refrigerant leaking or just the system equalizing upon shutdown?

[lothos]

Was it refrigerant leaking or just the system equalizing upon shutdown?

I'm not sure. I couldn't see anything spraying out of anywhere. It hasn't been very warm out today either, so I haven't tried running the AC.

[navion]

Well I got a can of 134a and borrowed some gauges. I added almost a whole can and got the PSI up close to where it should be. It was easier than I thought it would. When I turned off the car I could hear a hissing noise, that seems to be coming from the tube that goes back to the condenser, down in between the battery and the serpentine belt.

I was thinking of getting a can of 134a with the dye in it to find the leak, but unless there's an O ring or something down there that would be easy and cheap to fix I think I'll give up at this point and concentrate on the ball joint that I have to learn how to fix

I'd agree with Kevin & vote for the system equalizing upon shutdown. If the system had pressure & was just low, a leak that you can hear is unlikely.

My 94 SLS would, on occasion have a hissing sound on shutdown. but it's A/C worked very well & hadn't needed any 134A since I replaced the compressor in 2000! I hope that I get that kind of reliable service on the 2003 SLS that we just bought.

Britt