My question is, what is the R12 freon capacity of my trucks OEM AC system. My trucks AC data sticker is missing. The sticker should have a range in ounces like 20.8-27.2 which I found in another thread posted as sourced from AllData.It would be reassuring to heard what the 84-85 truck AC data sticker lists.
I have a 85 truck to which I am doing a DIY freon conversion to 134a. BTW I installed a new compressor, high and low pressure hoses, dryer and flushed the system. I have pulled a vacuum and the system is holding without a leak. I found a chart online stating 1lb. of R12 is equal to 0.65 lbs. or 10.4 oz. 134a
I have not replace the o-rings on connections under the dash. Only flushed the out any old freon thru the firewall connections. I don't know if there are o-ring connections under the dash and I'm hoping not to find issues with system components under the dash.

 

I have a Toyota Technical Service Bulletin somewhere about converting Toyota R12 vehicles to R134a and I believe it has capacities of both oil and refrigerant.

I will take a look tonight and post it up if I find it.

 

thank you. So far I've found R12 max. of 27.2 to 31.68 oz. and min. of 20.8 to 28.16 . Pretty much impossible to to figure. I am guessing, start by adding 20.8 and from there fill until the Lo and Hi pressure gauges are reading good. I got one reply that said R12 max. 1.98 lbs. and min. 1.76 lbs. on his trucks AC sticker. It's all new to me. It's no wonder the AC shops in my area said they don't do freon R12 to 134a conversions. Tomorrow I will get into charging.

 

Here is the TSB I was talking about. The R134a charge amount is listed in grams.

Unfortunately, it only lists trucks going back as far as 1986.

I am not sure what (if anything) has changed in terms of capacity between 1984-1985 trucks and 1986-1994 trucks.

 

Timely post, thank you. Looks like 24 ounces of 134a should work. I'll post my findings.

 

Update: My system would not accept a charge. Expansion valve plugged. Ordered new one, evaporator core and low pressure switch. Glad I was forced to open up the evaporator box because was full of small Oak tree leaves. Very doubtfulenough air would have pasted thru the coil to keep it from freezing up if the expansion valve worked.

 

I think mine took about 1.5 lb

 

Great. Thanks a lot for the PDF. This is exactly the info I needed. By the way, if you prefer manuals in PDF, you might find a free converter https://onlydoc.com/ocr-pdf I found a couple of days ago useful. It’s very convenient and easy to use. I’ve already converted a few of my own manuals and I’m very satisfied with the quality of the results.