2nd Gen Non-Engine/Transmission I think I messed up my A/C (overcharge?)

[AChaulk]

I hadn't put any Freon in my system for a couple of years. 2001. 5 Ram 2500 I broke my old gauge and decided to just get one of the kits with the low pressure side gauge on it. I purchased the "Synthetic" R-134A+ thinking it might be better then standard 134A. (Is there really any difference?)



I figured out that my pressure for a full charge @ 85 degrees and 10% humidity (In dry New Mexico) should be around 45-55 psi. I put in the entire 18oz can (which I thought would be enough to top off both my cars for the season. ) and it only came up a little on the gauge. Ran to the store and bought two more 12oz cans of the "synthetic" Freon and a charge of PAG100 oil charge. I shot in the oil charge using the hose/gauge combo that cam with the original bottle kit. THen I started to put in another 12 oz can. The pressure never got above ~30psi. I shot a THIRD 12oz can and still no pressure rise.



To make a short story long... I added a total of 42 ounces of Freon to a system that was already working fairly well and never had the gauge come up to the proper low end pressure reading of 45-55 psi.



After reading on the forum here that the total system should hold around two ponds of Freon and I've added more than that already, I have left the system off and am wondering what is going on.



I'm wondering if my pressure gauge on my filler can setup is not working properly. Is it possible that the oil charge that I ran through that line is messing up the gauge reading? My basic fluid dynamics knowledge tells me it shouldn't matter but I may be missing something here. Or is the capacity for my year make and model more than two pounds?



So now what do I do?

 

[tgee43]

I take it your system doesn't cool now, or doesn't come on at all. Was it totally empty when you started? If so, you probably have air in the system. Adding Freon to a system with air in it will make the high side PSI go through the roof and shut down. If it had Freon in it, and was just low, you probably added too much Freon, which will make the high side PSI go through the roof, and shut down. You really don't need to add oil to a A/C system ever unless you blow a line, which will blow a little oil oit, or replace a component, like a compressor. How much oil did you add? Too much is not good.

 

[HHhuntitall]

The low pressure side is directly related to ambient temperature and the function of the condensor and evaporator. You've definitely overcharged it, if it didn't blow it out the bypass on the compressor or you don't have a major leak... ... . Personally, I'm betting you have a massive leak. I don't know how you got that much freon in there.



Those low pressure guages are only so accurate. The only "correct" way to charge the system is to do it by weight..... I often top mine off, charging mine by guessing, but I use both sides of the guages, high and low, and watch for compressor cycles. Ideally, (IMO) most of the Dodge systems will run 9-15 seconds with the compressor engaged, then 10-20 seconds with the compressor disengaged, cycling along those time lines. That isn't always the case, but what I like to see. And adding oil to an operating system is a big no-no if you haven't lost a large amount of oil from a leak or discharge. Most of that oil will be trapped in the in the dryer/accumulator, stopping it up so freon can't pass, and it will also stop up your orifice tube, making your compressor build excessive head pressue.



At this point, I'd suggest evacuating the system, recovering the freon, and pulling vacuum to check for a leak. Then it can be charged by weight properly. I didn't have scales for years, but the cans are usually pretty close, so I'd suggest getting a large 24oz can and a 12oz can to charge it.....

 

[AChaulk]

Yea I guess I'll have to submit to the pros to get the right weight in there.

Just to be clear, this is not my first time charging up a low system. I've done it a bunch of times with no problems and no over fill. My truck's system was working reasonably well but just needed to be topped off. I should have gone directly to the TDR forum first to find out the proper charge weight and I might have been okay. My crappy Haynes manual doesn't say squat about that, unfortunately.

The truck has 120K on it and the A/C has never been serviced other then a Freon only top off about two or three years ago. I figured that after that many miles without any additional oil that it might be time for more in there. I thought two ounces of oil would not be too much to cause a problem.

BTW... . My other comment about the supposed "Synthetic" Freon. Is one Freon can of 134A any different from another?

Thanks for the help guys.

 

[HHhuntitall]

I've never noticed any difference between R134 Freon brands, synthetic or otherwise, in performance. To me, washing your condenser and evaporator out makes more difference than anything. Maybe someone here knows something I don't... ... which wouldn't surprise me!! :-laf

The best Freon is R12, of course, but that's no longer manufactured, as we all know, so after that, I'd suggest Freeze 12, which I heard is being banned, as well. I haven't talked to those guys, so I'm not sure. It's manufactured by TCC, Technical Chemical Company. After that, I'd go to Triflouromethane (R-23) or Chlorodiflouromethane (R-22) for best refrigant out there.....

But our systems are pretty much designed to run with R134, it's readily available to all, so that's the cheapest route at the moment. I don't know where they get "synthetic" from, or how it's made, so I can't comment on how it works..... Usually, if you buy the cans of stop leak, they'll have a heavier oil in them, and that's what's used as the "stop" leak..... That added oil is often a burden on your system, and if added frequently, it eventually will sludge your system down and burn up your compressor.

I've got several old trucks I've never touched. My '93 has the original R12 charge in it... . as does my '84 Case 2390 tractor... . They work fine and cycle like they're supposed to, so I guess they'll run forever... . maybe.

 

[hsmith]

Any freon with "stop leak" will not only eventually ruin your system but also those of us that have expensive service equipment. When my machine detects such, I send them on down the road.