AGreen

iTrader: (11)

I just charged my truck with R152a. I must say, it's good stuff, but the unfortunate thing is that the can is slightly larger than an R134 can, so the side tap actually ended up crushing the side a little. Now, since there's that little bump in the side, I really wasn't able to get all the refrigerant in from each can. I'm not diluting the fact that the R152a is wonderful, and it cools my truck down really well.

Also, I don't think one question was ever really answered. Is R152a a one-for-one swap for R12? Do you charge the same weight R152a as you would R12? Looking at the charts and seeing how similar it is to R12, I'd reason to believe that it should be a straight 1 for 1 swap.

My S-10 takes 2.5lbs of refrigerant, and I charged in 36oz (well, probably between 30 and 34oz, since there's that little dented side of the can). It's cooling great, but I wonder if I could get it better. If only I knew how much more or less R152a to use

jackhild59

iTrader: (7)

Well Howdy Doody, I was just about to post up on this thread again. One of the questions people had was charging R134a systems with $152a. I did this on my F150 last week.

AGreen, you are severely overcharged. The performance you are getting will suffer when the temperatures go up later in the summer.

The correct amount according to theory is as follows:
The molecular weight of 134 is 102 and the molecular weight of R152a is 68.
68/102=.64% So multiply your 135a factory charge by .64 and you have the theoretical correct charge for 152a.

Example: I just charged my 2002 F150 Pickup. Factory charge is 33 oz. 33*.64=21.12. I charged 2-11 oz cans into a deep vacuum. A/C is magnificent, 32* vent temps.

Molecular weight of R12 =120 68/120=.56 So on our beloved FC the correct charge is 29oz of R12. 29*.56=16.43 oz. In my post on page 2 I advised that a full hcarge on an FC is 20 oz, this was inaccurate and made the system overcharged. !6 oz is accurate. I always assume that an oz or two is lost in the unhooking hoses, because I don't have shut off valves on m,y R12 gauges. So 2-10oz cans will really yield about 18oz-close enough!

I do have shut off valves on my R134 guages, so when charging my pickup, virtually all the refrigerant ends up in the system.

I have lately been finding 152a in 6 oz, 8 oz, 10 oz, 11 oz and 12 oz cans (ain't Fry's Electronics wonderful?).
You could make a combo of the sizes to accurately fill just about any system.

AGreen

iTrader: (11)

Oh wow. So nearly half of the R-12 charge! Man, I guess you're right, I am severely overcharged.

2.5 lbs = 40oz
40oz*0.56 = 22.4oz

I have over 30oz in my system.

I need to.... recover..... the refrigerant and try again.


Speaking of which, how would one recover R-152 refrigerant, and what kind of ill effects would it have if someone were to evacuate my system using a 134a machine? Would the mixing of 134a and 152a inside the recovery machine have any weird consequences? How about the subsequent mixed re-charge into another (or the same) vehicle?

jackhild59

iTrader: (7)

Remember, this is a *duster* gas that is manufactured to be discharged into the atmosphere. It legally changes when you use it as a refrigerant, but it won't destroy the ozone/kill.polar.bears or anything like that.

I wouldn't add it to someones 134a stock by having a shop recover it. That wouldn't be nice.


Maybe you should use it to blow out your keyboard on your PC...

AGreen

iTrader: (11)

I know, I know. Just playing devil's advocate here

I'm just stating the obvious for everyone who does this: Be courteous, and don't neglect to at least put a sticker of some sort on your car if you decide to sell it to a non-technical savvy person who will be taking their vehicle to a service shop.

Can you imagine how mad and confused that would make technicians if their 134a machines got contaminated with a batch of 152!

I *cough* recovered the "refrigerant" from my truck tonight and replaced it with 2 cans of 152a, vs. the 3 cans I used yesterday. So approximately 24oz, but once again, probably a little less due to bleeding and what little bit got left in the lines, etc. So probably right at 22-23 oz, which is perfect. What a difference THAT made. I was a little worried yesterday when driving it around. It was making a little bit of a weird noise, and the engine was very labored. Now, it's no longer making that noise, and the engine runs just fine. The only way I know the compressor comes on is the little click noise, and that's if I'm sitting at a stop with the radio off. I figured that the noise and roughness was going to be inherent; it's a 21 year old truck with 240,000 miles on it. After recovering and recharging, it's smoooooooth once again!

Thanks a lot my good sir, your information on this new refrigerant is going to change the way I do AC systems from now on.

jackhild59

iTrader: (7)

Update:

I just added another car to my 152a fleet. My 2004 Mazda6. The A/C was kinda average. I've only had the car a year. It is an 'S' model with the automatic climate control.

Today was 88* here. First I tested the vent temps. Hmmm, not too impressive, mid to upper 40's on high recirc, confirmed some compressor cycling both while idling and while on the highway. That might indicate low refrigerant.

I tested running pressures. High side was a little too high for the obviously low levels. I suspect that the refrigerant is contaminated with air. If I had NOT run the car but instead had tested the pressure at a known temperature in the morning, I could have confirmed the contamination. Simply by comparing the known Temperature to the temp/pressure chart for 134a. If pressures matched, no contamination. If the pressure was too high, it is contaminated with air. If it was too low, it might be contaminated with another refrigerant.

I verified that both fans were correctly operating. Last summer I had replaced the dual fans (one fan had a burned out motor when I got the car.) and also had the cooling control module replaced under a Service Notice. Everything was working happy.

Confirmed that the recirc was sealing and that outside air was in fact outside air.

Then I replaced the cabin air filter. I replaced it last summer when I bought the car, but hey for $3 on close out at RockAuto, I have several of them on the shelf.

I evacuated, vacuumed and charged. When I was evacuating, I found that there was fluorescent dye in the system, so someone *had* worked on this A/C. Unless they were a pro, they probably put a hose full air into the system while messing with it. OEM charge of R134a is 1.1 lb which is 17.7 oz. 65% of that to calculate for the R152a =11.44 oz. So I used a 12 oz duster.

Now the vent temps are outstanding. 38-40* on the highway high fan recirc. on. That is a full 10 degrees colder than it was before servicing the A/C.

That is how it's done.