junk4u

iTrader: (1)

Stay with the good old R12 if its working like a charm. If need be you can change to R152a, you will need to flush the system and change out the expansion valve and dryer. My system is still setup as R12, I didn't change anything to the R134 setup as there wasn't a need too. Either way to install the R152a today you need the can tap the green tool you see in the list of stuff required. The other thing you should do and is require is placing a label on hood showing the gas installed. This is required by law because when servicing you want to let the person servicing know what is in there to avoid accidents and cross contamination.

Put simply just change the dryer and expansion valve flush the system and charge.

My94yota

Very cool, literally....I never even knew the gas from the duster could be used...My 94 22re pickup still has the R12 fittings (no updated screw-on R134a fittings) but the compressor on it says R134A on it, although its just a sticker so doesnt mean much but it was all done by the previous owner....So I'm not sure if it was converted to R134A and they didnt put on the label and took the retrofit fittings back off after charging or they just replaced the compressor from an application that was meant for R134A, I'm assuming thats what was done tho but is there any difference from a compressor for an R12 vehicle than an r134a vehicle? Just wondering..Thanks

And any new updates on anymore testing?

junk4u

iTrader: (1)

Thanks My94yota... I really don't have any update on the cooling of the A/C these days, only because the temperature around South Florida has been in the 70's mid-day and in the 40's in the evening, but right till the outside temperatures cooled down it's been blowing cold, so far it's been that way for the last 4 or 5 months, so nothing has degraded yet.

As for the compressor in your truck, I understand that today since the first R134a unit was released as well as retrofitted, they all are required to label the system with the type of gas being used. This would be to avoid contamination of gases when recovering and when filling the unit.

I'm sure there is a difference somewhere along the line with compressors, but in most cases way back the differences where more so the condensers and evaporators to handle the release of the temperatures. Condensers are larger in R134a units to release the heat and cool the gases.

By the way there are a few companies out there selling propane mixtures to use in your car, but since the classification that was put on it, it is illegal to install propane into a car. Propane is being used in commercial vehicles and machinery, mostly outside the US.

junk4u

iTrader: (1)

Okay it's been a little over a month since my last update on the AC. The temps here in South Florida are around 85 +/- mid-day. Really nice, The AC is still cooling very well, nothing seems to have change as far as its cooling.

There is one thing that should be done that most never ever pay attention too is the gap between the radiator and the condenser.



This is very important, I tested it out several times and fine that filling that gap helps the efficiency of the cooling of the condenser. The air is drawn through the condenser then through the radiator. Back in 1986 when I purchased my original 86 4Runner they had that foam I mentioned about. Being so dumb to the facts I thought it was there just to help with vibration or movements, but that wasn't the case, it was to keep the flow air rather than drawing air after the condenser. Hope that makes sense.

Go to the Hardware store and pickup a foam filler.





I've got a towel squeezed in there now and when you take it out run around for a day and the next day put in and see how much of a difference it will make.

junk4u

iTrader: (1)

I forgot to mention that it would be a good idea at some point for those of you who take your dashboard apart is to seal up those fitting on the air tubes for the AC. They are leaking and cause the flow to be so weak. I was driving the other day in slipper and my toes were cold, once I get the chance to get back there I will either re foam the fittings or alumi tape them to seal up those leaks.

JodyR

I just bought all new components for my A/C and will probably charge with 152a. Sounds like there have been at least 2 yotatech'ers having success. Everything still going good for you guys?

While I am rebuilding the engine and swapping the auto for a 5-speed, i figured why not tackle the AC too, right?

junk4u

iTrader: (1)

Yeah works great, Mine cooled until i started messing with the door lights tracing those wires, must knocked one of those wires or relays under there. From haven't had the time to get in there and check it out.

JodyR

After reading your build thread, I'm sure you will find it. Hopefully you want have to get all contorted up under there. I am dreading pulling out my evaporator.

I like the idea of 152a for all the reasons that you have listed, but for me, the biggest reason is because it will draw less power from the 22RE. Should also be better for the A/C components than R134a. Kinda like fine tuning our A/C systems, huh?

junk4u

iTrader: (1)

R152a was one of the choices of EPA to use as a substitute years ago. The pressures for R152a run much lower than R134a and R12, but temperature wise the readings were between R12 and R134a. So it would seem more efficient that R12 and R134, with temps almost as cold as R12.

JodyR

Hey Junk...

I am ready to charge my system with 152a and just to double check...

a 15 oz charge of 152a?

What pressures on low/hi should I expect with RPM's around 2k? Thanks.

JodyR

My sticker says:

1.65 to 1.32 lbs of R12. which equals...
26.4 to 21.1 ounces of R12...

R12 weighs 120.9 g/mol
152a weighs 66.05 g/mol

that gives you a multiplier of .55 so my system in my 88 4runner should take...

14.5 to 11.6 ounces of 152a correct?

junk4u

iTrader: (1)

Hi JodyR, Sorry for the late response. I've been so tied up with work that I haven't had time to do anything with my truck. I did see your question the other day pop up on my phone, but couldn't answer it at the time. When I did get to start to answer it I got called away again. This weather we are having in South Florida is causing all kinds of electrical issues which has caused a great deal of expense for the company in hardware security cameras computers and accessories.

On to you question. When I charged the A/C I charged by pressure not by weight. Looking over my data when I last checked the readings were as follows:

Ambient temps: 85-90 Degrees
High Side pressures: 190-195psi
Low Side pressure: 25-29psi
Vent Temps (2000rpm): 38-40 degrees
Idle Temps (850-950rpm): 41-45 degrees (my idle was up need to check TPS)
Date: April 26, 2014 Time: 1:36 pm

junk4u

iTrader: (1)

Answering this question separately only because I would lying to you if I said you are 100% correct on the actual amount of R152a, but it is close.

Doing it properly I would say I would have had to weigh in the can of R152a before i use any of it then weigh it out after usage as so required by EPA in most cases. I did not weigh those little cans of R152a, but I can say it is pretty close to calc, which is just about 1 can and a little more, I have a can left over almost full of R152a in the garage. Once I reached the pressure I was looking for I closed the can tap valve and just put away the rest, so yes you are looking at about 13 or 14 oz of this stuff to charge the unit.

Also, you should know that I had added a blockage between the radiator and the condenser which improved the cooling of the condenser a great deal. https://www.yotatech.com/52173656-post44.html

JodyR

Thanks for the numbers man! I thought they might be a bit different than the R12 numbers published in the service manual.

Hope you catch a break with these storms... been crazy here in NC too. Nearly got struck by lightning camping a couple weeks ago- we were tent camping in Pisgah National forest, 0% chance of rain in the forecast and later that night nearly 3" of rain fell in 4 hours. Saw, heard and felt the lightning strike at the same time - loudest thing I ever experienced. Thought a huge tree fell on us - scary! 10 minutes later, the EZ-up that I placed over the tent for added protection, fell in on the tent, nearly giving us another heart attack! Not much sleep to be found that night!

Anyhoo - I did have a good weight scale and measured before and after the charge, but I have an electrical issue preventing the compressor from kicking in. I can throw it manually and it will get good and cold, no leaks totally happy about that! I'll get it sorted out eventually. Thanks again for the great posting and first rate help.

coryc85

Jody - good to see another person trying this R152. I told junk I might try it when/if my current r134 charge stops working or if I have to open it up for any reason. When you said an electrical issue is preventing the compressor from kicking in...could it be that you need to adjust that little amplifier knob up under the passenger side dash? I believe that knob has something to do with what RPMs your compressor kicks in at.

JodyR

Thanks for that Cory...I'll play with that knob. I can't be that lucky though. I am afraid that it is something wrong with the ac amplifier. The A/C has not worked since I bought the truck - no idea why the PO disconnected the compressor and pulled the belt.

junk4u

iTrader: (1)

Hi JodyR

Sorry again about the delayed reply. I would start by checking the one cable running to the compressor to see if you have 12v when you hit the AC button on. If you do, then you could have a low charge or a bad clutch which is magnetic. If you could push start the clutch then I would check these first, it's right there and easy to access.

The other things to check are what CoryC85 recommends to check the amplifier. There is also the relay near the amplifier to the left behind the a/c console.

Hope this helps

nv4runner

After reading this thread I flushed, disassembled, resealed, and charged with r152a in mid June. Before that it was running r134a until an o-ring gave up the ghost on the compressor discharge line. I can still recall how the compressor would whine with the r134a. Right now its a bit over charged, but the vent temps drop to the high 20's out on the highway on a 90 degree day. City driving and idling gets the vent temps to around 55 degrees, which sure beats no a/c on these mid to high 90's days we've been having here. I'll keep adjusting the pressure until it cools better with slower driving.

Cold a/c and the compressor doesn't whine like it's going to explode! Thanks for your write-up.

anndel

My A/C mechanic used 100% pure Freon (R-12) 8 years ago and it still cools down to 36 degrees. He said he still has a bunch so not to worry for a while. I asked about retrofitting my system to use the easily obtainable refrigerant but he says it's not going to cool down as much and better to go with the R12.

nv4runner

If your R12 system still works then don't change it. R134a runs at a higher pressure than R12 to achieve the same temps, so it also needs a larger condenser to give the same cooling as R12.