Hey guys,

My ac has sucked since i bought it, and after hearing a bunch about some of these trucks coming form the factory undercharged i figured that is what mine was.

Well i bought one of those recharge kits from autozone, and hooked it up to the low pressure side. The gauge said 36PSI and the ambient air was 79F. So i started to add the R-134a. Well i ened up adding the whole can (17 oz. r-134a, and 2 oz. sub-zero synthetic).

After adding the whole can the gauge still shows about 36-37PSI.

The can dispensed into the system in probably about 30-45 seconds. If that matters..

Any Ideas what i should do? Think it needs more? I could it have been that low from the start?

Thanks,
Nick

 

On an '05, which I'm assuming is still under warranty unless you've driven it out of warranty by mileage, why not let the dealer worry about it?

A/C pressures cannot tell you how much refrigerant is in the system. They can tell you how the system is performing ("they," as in high and low side pressures, low side only won't tell you much of nothing), and give you a general idea of whether the system is low or overcharged, but that's it, a general idea. And if you're using that goofy gauge that comes with those recharger cans, all bets are off.

And what's "Sub Zero Synthetic?" Please tell me it's just an oil, and not some kinda cooling enhancer snake oil type deal. And if it is an additive of some kind of another, please tell me it's compatible with 134a. Because you may run into problems if someone recovers your refrigerant into their charging station with any additives or chemicals in the system.

With over an additional pound of refrigerant you added, you've probably overcharged the system now which ain't gonna make it cool any better than before. The best course of action at this point is to recover all the refrigerant to see how much is really in there, vacuum the system down and recharge it with the proper amount of refrigerant. Hopefully that Sub Zero stuff is just oil, but if it ain't, good luck because if a shop finds out your system has an additive in it, chances are they won't touch it, or you're gonna be paying for them to make it right.

 

The can says that the sub zero synthetic is Lubricant with stop leak.

 

Leak sealers react with any moisture in the system and turn into a gel. A gel that contaminates fresh 134a when it's recovered by a charging station.

And this, boys and girls, is why I'm a firm believer that A/C work is not DIY stuff. At this point, take it to your dealer, an A/C shop, whatever, and see what they can do for you.

 

Dealer wont touch it. I have E-fans on my truck. Which is why i tried to do it on my own.. I already tried two different dealerships and they wouldnt even look at it due to my e-fans..

My AC seems to be blowing much colder now though.. Hummm.. If it is overcharged now is it causing any harm or am i causing danger?

So looks like i need to find an AC shop. DAMN IT!

 

OK well i stoped by a goodyear tire today. they want $199.99 to revac and recharge the system with 34 oz. (what hte sticker calls for).

However right now my air is blowing much much colder than before so i really dont want to spend the $200 if i dont need to..

Is it really bad to be overcharged? What risks am i running?

Thanks,

 

Goodyear wants to HOSE you DEEP for $200 to recover, reclaim, ecvacuate and recharge the AC with a measured 34oz of R-134a?

My shop charges $35 plus the freon, which you probably don't need any.

 

Run it and see what happens. Ain't got nothing else to lose at this point.

 

Oh i have been running it since i did this yesterday. It is blowing much colder now. However im sure its overfilled now. I am just wondering how bad overcharged really is.. Is bad to were i need to go get it fixed?

What shop only charges $35+ freon? I need to find that shop.. BTW i walked out the door when goodyear told me $200.

 

Alright, first, all you tree hugging hippies ignore what I am about to say.

Second, this is info I as a self taught mechanic am giving. I don't give two chits if someone else doesn't like the way I do it, and if you dont like my advice don;t take it. (read: do it at your own accord, and if you don't like it I don't want your opinion)

Now that we have that out of the way, ac works is little more than childs play. Any boob can get the stuff needed to diagnose and repair an ac system at autozone. You don't need the $2000 evac/recharge machine to service your ac, and those ac diagnostic charges people pay are a crock of chit, like paying $80 for an OBDII read.

95% of cars have the maximum amount of ac that can be charged on the sticker under the hood. If its low, its most likely got a leak. First, check the valves. (the little schrader valves in the high and low ports) Using a tire stem tool, give it a slight twist to tighten if its loose. The easiest way to tell is when you remove the cap if it gives a small hiss then its leaking. If you don't hear the hiss, it could still be leaking. A dye kit is less than $50 and can do multiple cars. (read: fix your neighbors ac and recoup your costs for the kit) After inserting the dye, put some gas in it and run it. Then, using the ultraviolet light you can inspect for leaks (all instructions come in the kit)

Recharging is simple. Evacuation is not necassary. Sure, it may gain you 4 or 5 degrees cooler air, but if the system is working properly you won't know the difference in 5 degrees. Overcharging can lead to problems, but no always. I have had several system I add more than called for that worked so good you'd have frost hanging off your nose when on full blast.

If its working great, then leave it be. If it slowly gets warmer over the course of a couple days or weeks, you have a slow leak somewhere, get the dye kit.

People get ripped off everyday with diagnostic charges and other bullchit. When someone asks me to recharge or diagnose an ac problem, i tell them point blank.....I'll charge it, if it holds then you're good. If it doesn't, come back and I'll add dye, locate the problem, and we'll fix it. R134a has more than doubled in price in the last two years. Expect that a dealer (shop) is paying around $7 a can, so don't pay more than $18 a can(pound) or so. Its so easy to do this stuff yourself, it rediculous. I hate to see all these people get ripped off. Thing is, alot of people have this stupid mentality that if the shop isn't ASE certified, they don't know what they are doing. ASE=ask someone else. The only part that is worth having someone else do that is a royal PIA is the evaporator core. (in dash)

 

If it's grossly overcharged, the pressure relief valve on the manifold line might pop open every now and then when high side pressures reach about 425 psi. But if the pressures get that high, you've got other problems besides being overcharged.

 

I'd agree with you on most of your points, but without knowing how the system works and what different additives and chemicals can do, I don't advise anyone doing anything to their A/C beyond turning it on and seeing if it works.

And therein lies the problem...

Be advised that a lot of cars nowadays use valve cores that are a lot bigger than those used in a tire.
Ford adds UV dye in all their A/C systems from the factory, they have since about '95 or so when they started the switch over to R134a.
This I don't agree with. Not just for maximum system performance, but for removing moisture from the system that becomes corrosive when it comes into contact with refrigerant.
I hate seeing people who shadetree and DIY their A/C stuff, only to make it worse than what it originally was. Then they're usually out more money than what they would have been in the first place letting someone who knows what they're doing do the work. And then there's the obvious safety factor. Yes, A/C work is relatively simple. But all it takes (especially if charging with a manifold gauge set) is opening the wrong valve at the wrong time to earn the nickname "Lefty" for the rest of one's life.

 

People have told me that for years, yet I would put it to the test by having two identical cars next to one another, tech a using a machine and the "appropriate" way, while tech b simply took it apart, replaced the bad componets, and recharged the system. They'd both work just as well as the other, and I'd bet lacking some sort of unknown they'd last the same amount of time before needing another repair. (I know cause I have done it that way) I won't sit here and say that evac'ing the line won't help a little, but I have done it both ways and had the same results reguardless. You don't even need a manifold gauge set to do it, just the basic line that comes with the kits at autozone. I have been doing ac work for several years for my customers with a simple can, valve and line and never once had an issue. Then I hear horror stories of these $1000 ac repairs that can be done for less than $300

 

Then we'll agree to disagree.

 

I;m fine with that. I just like to try and save people money. But your my ga bud, and there are several boneheads in this world that need not even change oil, much less work on ac