maddogandnoriko

So it is 94° and 46% humidity here in Florida and, of course, that means it is the best day for the A/C compressor to fail. Took our '93 4runner V-6 to a shop ad they told us the compressor was bad. So I have been reading about repairing it. I have access to an electric a/c vacuum that I believe can be used to evacuate/reclaim the r134a Also, 6 years ago we had the a/c converted to r134a. Here is what I have as far as steps.
1. Evacuate the r134a from the system.
2. Loosen tensioner and remove belt.
3. Remove the bolts holding the lines to the compressor.
4. Remove the bolts holding the compressor to the bracket.
5. Remove compressor.
6. Reverse to install new compressor.
7.Change the dryer (do not open until ready to install).
8. Possibly change the expansion valve.
9. Possibly replace o-rings that are r134a compatible.
10. Use vacuum to clean out system of junk and air.
11. Add ester oil, important to avoid anything with PAG oil(not r134a compatible).
11. Recharge system with r134a.
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Look right? I have never worked on A/C before and have a question I hope you can answer.

1. I have read that new compressors come pre-oiled with a PAG oil. Is that true and will it get removed when I vacuum the system out?

2.Is there anything that comes with a new compressor that needs to be changed due to conversion to r134a?

3. Have I missed anything? This seems fairly straight forward, but the conversion brings up a few things.


Thank you so much,
Todd

Unrelated, we just had Toyota put a remanned engine in, cost a bit, but my wife loves our 4runner! Here's to another 225,000 miles!

scope103

Here's all I know about A/C: https://www.yotatech.com/forums/f116...-r134a-284801/

A regular A/C vacuum will not reclaim anything. I don't think there is any workable DIY to do that, so you'll need a shop for that step.

All of the compressors I looked at warmed ominously that there was NO warrantee unless I could prove that I both replaced the expansion value, and flushed the system. While my system turned out to be pretty clean, often enough a failing compressor shoots crap through the whole system. You'll need to get that out. A vacuum will remove air and water vapor, but it won't remove "junk." While technically you CAN flush a system while still installed (if the TXV is out), it's pretty clumsy. I found it much easier just to remove each component, including the evaporator.

I'm not sure why you want to avoid PAG oil. So far as I know, PAG 45 is specified for Toyota R134a systems. My understanding is that "ester" oil can be used if you still have mineral oil (used with R12) in the system, which is not your situation.

Think about how you will recharge the system. Using "A/C in a can" from your local Wally Mart is a waste of time; you need two gauges (a regular manifold gauge), you need a way to measure temperatures, and you need a scale. Using a single gauge on a squirt can is only guessing.

Consider using fluorescent dye. Unless you are absolutely certain you will never have any leaks.

My compressor came pre-charged with the necessary oil.

jjrbus

I can only tell you what I did. After 100's of web searches and much confusion, I found if the compressor has failed the system must be flushed. Also I had 23 year old hoses that I might as well replace as long as everything is apart, have to have a new dryer and expansion valve. So as long as I have it all apart I simply replaced everything and I mean everything, In actuality the only things I added were the evaporator and condenser. The only thing I did not replace was the pressure switch, that damned thing leaked and I had to take apart and replace!

All the time I am doing this I have someone telling me to just replace the compressor and go to Wal Mart and buy some magic elixir for conversion. What he does not mention is he has replaced 3 compressors in the last 5 years!