The claim that a refrigerant can be charged in over air is a misinterpretation and/or a myth.

For best performance, you need to get all of the air out of the system, period. Some techs will force-ably 'blow it out' using the refrigerant, but this is hit and miss. Best way is to pull a deep-ish vacuum.

There is another option: if the system is still under some pressure from a previous refrigerant charge, you can properly release that to atmospheric pressure and charge the ES over the top of it. (I believe this is the condition that is presumed in the instructions for the ES product--however, we're further assuming the system was properly evacuated and functioning at some point.)

In any event, air must always be removed from any a/c system, otherwise the air will become trapped mainly in the condenser and system will not function at full capacity or efficiency.

 

From the autorefrigerants.com site:

I charged my system today using the ES-12a. I only used 1 can and I'm seeing 175psig on the high side. I know that's low.

The car is blowing cold air though - but I would like it colder...

Going to charge with another can to get it a bit higher. What is the high-side PSI rating on our cars? Can't find the number.

 

Last night I drove around 45 minutes away from the house mostly highway. I was getting temps of ~40f out of my vents. I was freezing my *** off, my fingers were frozen and I had to turn it off and roll my windows down to warm up the cabin. This was with es12a no vacuum 2 cans.

 

From page G49, '94 Body Electric Manual

 

There is no high side rating.

The pressures depend on a number of factors...ambient temperature and humidity, how many BTUs the compressor is putting out, and what refrigerant you're using. If you're using the BBQ gas that is supposed to mimic R-12 then you should shoot for a high side that is 1.8 to 2.1 times ambient temperature. So if it is 100 degrees out then 180 to 210 PSI....although I've read that BBQ gas runs at slightly lower high side pressures so you might bump that example down a bit.

 

2 days ago I released my 134(atmosphere, Jiffylube turned me down since I didn't know if my system had any r12 shiz in it) then refilled with ES-12, and I'm sad to say the system isn't cold at all, I'll measure what temps I'm seeing but the cabin still feels like hell. I didn't charge under a vacuum as followed by the directions. Maybe that's where I went wrong or I should of replaced the dryer/evap...

But for the record, ES-12 makes a huge difference on how little of drag it has on the motor compared to 134.

 

Measured my temps yesterday, again this is with ES-12(no vac or replaced parts): after startup in the garage it was blowing 60* f; driving around once everything was warmed up it was then 70* and sadly coming to a stop raised it more to 75~*. I'm definitely not satisfied so I will be replacing a few parts...

 

Here's an update with my experience:

So I only charged using 1 & 1/2 cans of the ES-12a from auto-refrigerants.com

Within minutes of charging the system started to blow cold air. Not super cold, but cold enough to drive with the windows up and not sweat.

Well it's been a couple of days and I've been driving the car around and the A/C seems to have gotten even colder. Now after a few minutes of driving the A/C blows so cold I have to turn it down to the #2 blower setting, otherwise it feels like I'm in a freezer.

Here's how I charged: cleared system to make sure there was no pressure or vac. Installed a new dryer canister. Charged with the can of "Stop Leak (O-Ring conditioner)". Let it cycle for 15 minutes then vented the system so no pressure or vac. Then Installed 1 & 1/2 cans of the ES-12a using an A/C manifold gauge set (not a simple charging hose). I made sure to charge the system with the ES-12a as a liquid (held the can upside-down up in the air while opening the manifold valve to maintain about 50psi on the low side. I kept feeding the ES-12a until the can was empty making sure to keep the low side pressure under 55psi (it says not to allow it over 60psi). After it was charged with 1 & 1/2 cans I drove around for a bit with the A/C on high, and it immediately started blowing cold air.

Hope this helps.

 

You did a lot more than I did theorie lol, I just used the charge hose put the cans in and drove around. It gets freezing in the cabin, I start with the fans on 4 and after 20 minutes I have to put it down to at least 2 or I am to cold, this is in the FL 90 degree weather.

The other day I drove it with my wife and she was saying it is to cold, she drives a Corolla.

edit: it took about a week before I saw the coldest temps. I am going to buy a kit of it for my mustang as the ac sucks right now. Gotta bring it to the father-in-law to take the old freon out instead of letting it leak to atmosphere lol.

 

Last winter I pulled my dash to fix the leaking heater core and I disconnected the A/C lines for few days; I'm assuming moisture entered the system which I'll need to vacuum out. Now I need to order 2 more cans of this ES-12 and try again... Just debating on trying another compressor and what additional parts should be replaced?


*EDIT* Found dryer for $17.99 at local parts shop.

 

Theorie, did you ever measure the temps coming out of the center vent? The FSM says after 20min @ 2kRPM you should be seeing 37-42* F.

I need some help as I'm not having the best of luck with this. What I've done:
System was previously converted to 134 which sucked so that was expelled;
I removed the compressor and drained the contaminated oil;
Replaced the Dryer with new and all o-rings.
Recharged the system with new oil from ES;
Vacuumed around 25~ for a good 6+ hours (no leaks);
With a vacuum present I connected the industrial ES-12, purged the line of air and began to fill. Never exceeded past 55psi using manifold gauges.

As industrial ES-12 says you CAN charge using a vacuum but you charge by weight correct? As I used both cans of the 6oz refrigerant I believe I overcharged the system now. The FSM says capacity is 21oz and each 6oz can = 18oz of r12. At this point I'm not sure what to do, I could relieve some pressure but not sure how much and proper way of doing so. I have a vacuum pump and manifold set also.

Any help would be much appreciated. Thanks.

 

First of all a vacuum of 25" of mercury is not sufficient. You need a proper rotary vane vacuum pump that will pull your low side gauge all the way down to to 30" and hold it there for at least an hour. The purpose of pulling a deep vacuum is twofold: To remove all the air from the system, and also to boil off any moisture in the system.

Now, what is the system doing or not doing that makes you say you need help?

 

Thanks for writing back. The air pump is single stage rented from Autozone and according to my manifold gauges it only pulls 25 and nothing further, maybe it's a weak pump? I'm disappointed about the air pump not being suffiecient now, but I cant turn back now unless I start all over again.

My question is really what to do from here, as I overcharged the system how could I fix it. With no real charts to go off of with this new stuff I shooting in the dark.

However I called ES today, the guy says 40 on low side at 90 ambient. I'm going to release some of the pressure down to that mark and hopefully she gets cool again.

 

2 cans of ES should not overcharge an FD. Before you do anything.....more info is needed.

What are your High & Low sides pressures, at what RPM and ambient temp.?

Is there adequate airflow through the condensor? Is this a stock setup or do you have a frontmount IC, etc.?

Is the amount of oil you charged into the system the same as the amount you removed from the compressor, and was this added with a refrigerant charge?

 

Totally agree here.

You need to have the A/C on full cold, full fan, and about 1800 RPM.
Then measure your low-side.

Did you fill it SLOWLY ?

Mine is cold at idle, ICE-cold while moving at 15-mph.

2-cans is perfect.


:-) neil

 

Sorry should of mentioned my setup which is stock at the moment.

I assumed I overcharged it since the ES-i12 says each can(6oz) is equivalent to 18oz of r12. In the FSM it says the system capacity is 21oz. So using two cans would technically be 36oz of r12 correct?

I filled the system slowly while keeping pressures < 55.

The can of oil contained 4oz and I drained almost 3oz from the compressor. Assuming exposed/leaky system of the years some has leak out so I should be on par there.

The ambient temp is 90 +/- 2. Oddly the low pressure was reading read 50 at idle now it's 65 and high side is 200 @ 900rmps. around 2krpms the I'm seeing 40low/250high.

Also note that I see bubbles in the sight glass while idle and 2krpms.

Thanks for the help, I greatly appreciate it and the fiance will soon too!

 

21 oz is too low, not sure about that figure--may be a typo or just wrong.

In any event, your other parameters seem in the ballpark. Normally, I charge in the usual manner and until till there are no bubbles in the sight glass (blower on high at ~2500 rpm). 40 psi on the suction should make plenty of cold air.

Have you verified that your temp control door is working properly and not reheating the a/c?

I have also experienced a situation with the ES12 where it took some run-in before the a/c really worked well--this is apparently not an unusual phenomena and I have heard of others with this same experience. Not sure why this takes place, but it may be because of redistribution of oil within the system and/or re-mixing of the refrigerant components if they have become fractionated. Oil is much more miscible in an HC refrigerant (e.g., ES12) and carries better, which can overload portions of the system with oil, especially if it is overcharged [with oil].

Under proper conditions, the system will maintain an evap temp of 32-->35 deg F. Outlet air will typically be 10 deg F higher, or approx 45 deg F, depending on blower setting, system load, ambient temp, etc.. Note that the evap thermoswitch will cycle the compressor if evap temp drops below about 32 deg F to prevent freeze-up.

I would suggest that you run it for a while and see if there is any improvement before you make any changes.

 

Great advice, thank you. I've read a lot about the system settling in over a period of time, I'll recheck it in a weeks time. Mean time I'll keep my eye on the temps also the sight glass. So actual vent outlet temps should be 45*? That's still better then the 60* I'm seeing at cruise w/ac on full blast.

I've been using the PDF from iluvmyrx7 which is the 93 FSM for reference and it's where I've been getting my numbers from.

Which door is the temp control? On the evap case there's the two arms, isn't the lever closer to the rear of the car? What's the front lever for? Perhaps this could be my problem, I haven't looked into that area much.

 

Yup... just did mine about a month ago with two cans as Neil has described. Ice cold on setting 2. Mine were 12 oz cans of R-12 and we used JUST under 2 cans, so 21 oz for system capacity sounds about right.

 

What brand and where did you buy the r12 from? If this ES doesn't work out this round then I'm ditching it :/

 

Yes, 45* nominal is what I can get with the fan on high; setting #3 producing slightly lower temps. The lower settings cause the compressor to cycle to prevent evaporator freeze up, raising outlet temps slightly. I am able to get this performance in the 114* ambient of Palm Springs, so long as the car is moving.

Maybe I'm reading this wrong, but my impression is that Neil was describing 2 cans of ES-i12 (and not conventional R12). Those cans are typically 6oz net, IIRC, which would be equivalent to 28 to 36 oz of R12, depending on the charging ratio you use. Even if you were to overcharge some, performance shouldn't be affected [as] much with the ES product.

What is the lowest suction pressure you've observed, particularly when raising the RPM's? Have you noticed any compressor cycling?

 

Thanks again for the info. Later today I'm going to loop the heater hoses and see if that drops my temps as I might be reheating the air :/

Were you asking me or RCCAZ 1 on the lowest suction pressure? I'll have to double check when I get home but I think 35 is the lowest dip.

 

Also do yourself a favor and do not try charging r12 before you sort out your problems with ES. There's no magic to refrigerants - if your system doesn't work right with ES, it won't work right with R12 either. And R12 costs a heck of a lot more money.

ES is pretty easy to use and it's not overly sensitive to your charging technique. You may have some problem elsewhere so keep listening to these guys before giving up.

 

In breaking news today..... I just checked the hood sticker on my '93 with a MANA a/c system and it calls for 28.2 oz (0.8kg) of R12 refrigerant. Now this is starting to make sense and my sanity is intact. Perhaps it is the Denso system that holds only 21oz.


Sorry for the confusion, I was obviously experiencing stack overflow at the time I asked. The question was directed at you, bufferovrflo. In any event, if you were hitting 30 to 35 psi at 2500+ RPM on the suction, I would consider that to be normal--not an overcharge.

What was the vehicle (propellant) used to get the replacement oil into the system and which side did you put it into?

 

Lol nice call.

So today I found my problem. I was reheating the air charge... I looped my heater line and now I'm seeing 40's from the vent. Although there's still bubbles in the sight glass while the compressor is on. Also the oil charge was from the can provided from ES kit.

I'm getting pressures of 40-45low/150high @ idle and 30/200 at 2krpm. I'll keep an eye on the system and see if there's any settling over the next week. Thanks again for all the input, now I have to find a replacement evap case :/