A/c service assistance and opinions.
 

Here's my story.

My car sat for 6 years, and had a AC hard line replaced so there's no refrigerant in it.

I want to switch to es-12 but I'm worried about having low or old compressor oil and am considering servicing my system by removing it and flushing the lines/ replacing the dryer and than filling it with the envirosafe compressor oil.

Does this sound like the right way to go? Or should I just charge it and see what happens?

Cheers.

Ya i would flush and re fill the system with oil also If it sat for that long I would think most the seals would have gone bad since oil travels with the refrigent through the system (10% of the compresser oil)keeping seals lubed and from drying out have u had the system checked to see if it holds a deep vac for 12+ hours since replacing the old line also might need Dehydrateing since the system was opened and most likely air and water are now in the system

Thanks for the response.

New gasket kit ordered, system is getting disassembled and flushed. New expansion valve ordered, drier aswell.

I can usually get any of these ac systems to blow ice cold without anything extravagant. I convert them all to 134A. Personally I've never felt a need to look into any of the R12 replacements. A proper conversion will be within a couple degrees of an R12 system. Typically when I'm doing an engine job I'll disassemble all the ac lines and flush them with brake cleaner and blow them out with compressed air, then replace the orings, put a little pag oil and uv dye in each line, and reassemble them. Its a good idea to replace the expansion valve. The dryer can be difficult to source depending on which ac system you have, so I will remove it and bake it on low in a toaster oven to dry out the desiccant. I then vacuum the system out for at least half an hour and ensure it holds vacuum. This will remove any remaining moisture. Then charge the system by weight with 134A. I build 500 wheel hp cars with ice cold ac if that is what the customer requests.

Thank you Ihor for caring to fix it right! I hate the "just tear it out and throw it away" mentality. A high performance RX7 with cold A/C in a hot climate is a thing of beauty!

I like to keep ac. When its off you aren't losing any power and there really isn't that much weight savings in removing it. People don't realize how much more enjoyable it makes the car when you can drive it for an extended period of time comfortably and how much more tolerable it makes it to wives and girlfriends.

How much 134 are you putting into a R12 car?

The shop I work in has a machine with a scale to put the exact amount in. It is invaluable when servicing the VWs I normally work on with variable displacement compressors.

Thanks,
Vince

In actually keeping it r12 I've sourced it locally for less than es12 would be.

As far as capacity... I'm under the impression it's 22oz of r12 and 5oz of mineral oil.
I still need to confirm that though maybe someone can enlighten me. 93 denso system.

And rock auto has driers for 7$ and expansion valves for 11 or so. Just a heads up.

They sometimes have them but there are 2 different driers depending if you have a Denso or MANA system. I prefer the oem parts whenever I can get them.

PAG oil should never go into any system that contained R-12. Ester oil would be a much better option.
Reusing the driers on pre-1995-1996 cars and converting them to synthetic oils is also a bad idea. The old driers were not tolerant to synthetic oils and can cause the drier bags to rupture,

That is true but not an issue when everything is flushed. I've had cars with ac I've serviced still making 500 wheel hp and blowing ice cold 5 years after the fact. I prefer to replace the dryer, but there have been times when it wasn't available.

Factory fill is 1lb 5.2oz fyi.

That spec is for R12? Would 134 be a different number?

134A. I'll look up R12 tomorrow when I'm at the shop.

These are Mazda's official specs on oil and refrigerant capacities when converting from R-12 to R-134a:

Imgur

The same document also indicates that the condensers on MANA cars should be replaced with P/N FD31-61-480

Thanks for this. Last night I was able to flush my evaporator, all my AC lines, and condensor, replace compressor oil and put all new gaskets in all the lines, also replaced my expansion valve.
Took about 4 hours, not too bad of a job, the amount of dye In the system was incredible! What mess! But I'm happy everything is fresh, now to rent a vacuum pump.

i;m personally a fan of using air duster as refrigerant. i've used it in my last two FDs and have charged a few friends' cars with it as well.

whats key is pulling a good vacuum, using the correct oil, and not having any leaks.

my current FD will cycle on/off with the evap thermoswitch when it's 95*F outside at the vent temp of about 40*F. (sitting still at idle when it's that hot outside will result in 50-55*F vent temps).

the air duster refrigerant is super cheap ($4 for a big can) and is molecularly similar to R134A. check into it.

I too was going to use es12, I actually ordered some, and a new dryer and expansion valve,

while waiting for it to arrive I pulled a vacuum down for an hr on the old dryer , and it had slow leak, went from 29 down to 25 after about 14 hrs,


got impatient so decided to shoot it up with r134a and ester oil and dye to at least see if it works and find the leaks... estimate I added about a can and a half of r134a,

with it 82 degrees out( may have been a bit warmer with car half inside the garage , low side 40, high was 210 slowly creeping up to 250 idling, on high. vent temps were about 56 degrees,

cruising down the road was seeing vent temps 40-44 on high,

here we go today about 92 degrees out cruising going 35-40

http://i60.tinypic.com/653135.jpg


compressor cycled when it got down to 37.6 degrees