Switching AC to R134

[YakkoWarner]

The more I read the more I think Sanden is going to be the way to go for me, but making it fit where the factory R4 is now will require some seriously advanced fabrication skills and tools, of which I have neither...

 

[75gmck25]

I used a Vintage Air Sanden compressor and Alan Grove brackets for my ‘75 350 engine with v-belts and it all mounted very well. The compressor is high on the driver’s side. It may not work the same for an ‘89.

 

[Ricko1966]

My Suburban never got comfortable with the original system running 134, it had been messed with before my purchase and I expect all they did was refill it with 134 and hope. My intent is to use the earnings from next spring's seasonal job to do a major rework (A6 compressor instead of tired R4, parallel-flow condensor, new dryer/accumulator and orifice tube, green O rings, etc).

Almos everyone recommends flushing the remaining lines and system which sounds like a great idea, but no one ever mentions what they should be flushed with or how.

Put electric fans in front of the condenser first and check your actual charge pressures first. You may have incorrect charge and the fans will help. May save you a chunk of change.

 

[bobhpow]

Flush out entire system, change o-rings, install correct amount of oil, install a/c dye when adding coolant. Vacuum for 20 minutes, watch for leaks. Do not leave lines open, try to keep them capped. This is short and simple how to do it, not quite this simple.

 

[chris3353]

Call Cold Hose,, aka air parts.

They have everything, I do these often and there is very little value in saving anything old. I have tried and it was not worth it. 134 will operate at a higher pressure and what may have not leaked before may suddenly become your demon in the future.

Cold Hose sell true "sanden" compressors, not chinese sanden style.

also,,there are a few different sandens, that have different operating curve vs RPM.

chris

 

[82SquareBurb]

Almos everyone recommends flushing the remaining lines and system which sounds like a great idea, but no one ever mentions what they should be flushed with or how.

I had good luck with denatured alcohol (sold as "clean burning fuel") and acetone. I used a cheap flushing tool on amazon hooked to the air compressor. Took about an entire gallon of alcohol to really get all the old mineral oil out. I used acetone to flush both evaporators. All the details are over in a post I made during that project: https://www.gmsquarebody.com/threads/source-for-rear-ac-fittings.46769/