AC system service

Im not very experienced with stock ac other than rering and vacuum and charging. 

Im converting my 95 Silverado with the old r4 compressor to 98 spec with the sanden compressor. 

The parts truck still had system pressure after being parked for a year or so. Im assuming it worked then. 

I removed everything from tbe parts truck except the evaporator under the dash. I will be swapping everything over from the 98 to my 95 but the evaporator. 

I have gotten the ac system flush arrosol cans and done the lines, codensor, and evaporator core per the directions on the can. 

I purchased a new seal kit. New oriface tube and dryer as well. 

What do i do with the used but assumed good compressor? The system,when drained,  had aTON of oil in everything,  and the oil was fluorescent berkeleying green. Im assuming theres still an unknown quantity of it in the compressor as well.

So. What do i do, and how do i proceed to give myself the best chance of successfully getting air conditioning back in the truck?

I'm not an ac tech, but that green stuff is the dye they put in the system to check for leaks.  Get as much of that out as you can.  See if you can get the compressor drained of oil and then refill the compressor with the proper amount and type of PAG oil for refrigerant you are using (for R134 i think its PAG 46).  What usually happens is the system leaks down because of a bad o-ring or pinhole in a hose, some yahoo puts a can of that dye stuff (i think it has oil with it) to check for the leak and the system gets refilled with refrigerant.  Do that enough times and you have too much oil and not enough refrigerant for the system to cool properly.  

Yea, the proper way is to fill with the recommend quantity of oil and plain refrigerant. With used parts there will always be some level of guessing. You also need to draw and vacuum on it for the prescribed period of time to get any and all water out before filling. 

So, what should I do to clean the compressor out? Compressed air? Superclean and water? Gas?

In reply to Dusterbd13-michael (Forum Supporter) :

Leave it alone, is my opinion.  You are more likely to put contaminants in the compressor if you try to clean it out.

If the compressor came from a vehicle with good working A/C and there was no schmutz in the discharge line, there's nothing that needs to be cleaned out.

If there is schmutz, or the ports weren't kept covered and dirt got in between the old vehicle and now, it's better to just get a different compressor.  Nothing you can do that isn't a complete teardown is going to help much.

I agree with Pete. Some of the modern AC recharge kits are light years better than they were just a decade ago. These kits are designed to work with systems that are mildly, or even moderately, contaminated with moisture, etc. Some are based on NASA 'repair refrigerants' that are for use while in space (no joke). So, you might just run with it as long as the comp shows no signs of bad stuff. Note; ~ 7 years ago my wife bought dirt cheap thrashed, but well running, '94 Caravan to use as a dog hauler. The AC system was completely disconnected from the condenser (and had been so for some time by the looks of things). I went ahead and replaced the cond seals and tried one of the above charge kits (I did not vac the system). And, low and behold, that system (once fully charged) blew very cold air reliably until we let the van go about 3-4 years later. Think I might have recharged the syst just bit 2 years on.

If you can find a good A/C shop, they might be able to rebuild the Sanden while you have it out.  Even if you can't, a reman compressor isn't terribly expensive, like $150 or less.

My concern is that finding pressure in the salvaged system doesn't mean the compressor was good, it just means the system didn't leak.  If you want to clean the old compressor you could buy a bunch of PAG for it and cycle it through I suppose.  I would just hate for you to go to all the trouble of bolting on a used compressor and purge/charge only to find out that it is wasted and now you not only have to re-do a bunch of work, but you've potentially sent shrapnel through your system.

I'm a little un-GRM when it comes to some things.  A/C stuff is one of them, and the big reason is the labor involved with doing it more than once.  You also have to rely on an A/C shop for one thing.... reclaiming freon.  Since A/C parts aren't that expensive, I just get the parts and do it once.

In reply to Curtis73 (Forum Supporter) :

I had a thought... Not reading brilliantly, I'd been assuming that a 4.8/5.3/6.0 is getting swapped in to where a 4.3/5.0/5.7 used to live.

If it's swapping one compressor type for another...  just get a reman compressor.  The compressors mounted on top of the engine had a dismal service record, they were generally either bad or just replaced.  Apparently making the compressor the highest point of the A/C system causes it to starve for oil, and they die rapidly.  So there's really no sense in installing a used one, unless you want to replace the condensor and stuff WHEN it grenades.

Note that the Gen III engines mount the compressor down low, where servicing is difficult... but then, they almost never die in service.

Fair enough guys. And im not sure E36 M3 didn't find its way into it while its been stored, as the tape i had over the ports fell off. 

Who makes an ok, inexpensive ht6?

Rock Auto, Four Seasons brand is what I go with.  Should be $150.