Another AC Thread: Which compressor??

I ha e for several years now been saying I was going to replace my AC in my truck. I have the A6 compressor in my truck. I'm sure it's not original but has been replaced. Question I have is should I buy a reman A6 AC Delco unit from Rock Auto or should I go with one of the new aluminum A6 style compressors they sell and it says various manufacturers that they list at RockAuto so I'm sure that's like four seasons and who ever else makes AC compressors. I have heard plenty of people say the new style Aluminum ones have had good success, but I'm not sure what brand there buying but I would venture to guess there not many factories that make A6 style Aluminum compressors.

Also I am not planning replacing with the different style of compressor, not interested in buying new lines and fabricating or buying new brackets or hunting down some. Rather just replace it as is. I don't drive the truck much, I do my own work, have my own machine and my own freon so that's not an issue.

Rebuilt A6’s are incredibly heavy, and often quite unreliable. I went through two before I switched to a Vintage Air Sanden and had new lines made.

The most frequently used direct A6 replacement seems to be the Pro6Ten, and it is supposed to be an exact replacement for the old A6. It should fit the brackets, and the fittings for the lines are the same.

Are you also doing an R134 conversion at the same time? Most new compressors use PAG oil, so you will need to flush the system and replace the accumulator, replace the orifice tube ( and maybe use a Ford blue orifice), and use the new green O-rings. It’s all fairly simple work, but it takes time.

Bruce

Everyone I talk to says go with Sanden. I bought a cheaper one but I can't comment on it too much just yet as I installed end of last summer.

A6 compressors are durable, but very heavy and way overkill for the intended application. Years ago I had to attend a training class for Cadillacs new climate control systems. The instructor said the old A6 compressor had the capacity to cool a small house.

The A6 compressor is definitely a outdated design. It was outdated when they were new on these trucks. The design goes back to the 50s when everything was overbuilt and over engineered. Since it’s so big and heavy, the internals don’t deal well with the new climate control designs used in the later trucks. When you turn on the A/C with a A6 compressor, the compressor doesn’t cycle on and off. The driver would definitely feel the compressor engage/disengaging. That’s the biggest reason GM went to the smaller R4 compressor, you can cycle those on and off and barely feel it.

The problem with the A6 is the design of the front seal. The seal is designed to leak a small amount of refrigerant to keep the seal lubricated. The refrigerant naturally wicks a little oil with it. Go look at the bottom of the hood of any GM vehicle with a A6 compressor, you will see the streak of oil on the hood felt parallel with the compress clutch.

The problem with the design leak is obvious from an environmental point of view. Remember the fluorocarbon a d Ozone concerns from years ago? Throw in the massive weight and fuel economy concerns, the A6 had to be retired.

The reliability concern didn’t begins to show up until the A6 was a footnote in history. Most A/C techs today know nothing about them. Since the compressor is designed to leak oil, nobody adds oil to them during the routine charging. Since the seal is designed to leak a little, it was common to have to top off the charge annually. Eventually, all the oil leaks out, abd the compressor locks up.

The A6 compressor was also used on lots of farm equipment, big trucks, heavy equipment,etc.

It’s hard to beat the durability of a A6, assuming it’s rebuilt correctly. To be honest, other than replacing a couple of clutches, I have never had one apart. If you have no desire to make new hoses to fit another design, I’d get a remanufactured compressor from a reputable company with a good warranty.

I have gone thru about 4 A6 compressors and now have one that has worked well for about 2 years. If the current one goes out, I am thinking about converting to Sanden. I found this one that should connect to current hoses. Don't know anything about them.

https://nostalgicac.com/a6-to-sanden-conversion-kit.html

I have not had any trouble with the A6 I got from Advance. And if I ever do, the lifetime warranty will cover it. It was a simple thing to install. I can't really complain.

Charlie said:

I have gone thru about 4 A6 compressors and now have one that has worked well for about 2 years. If the current one goes out, I am thinking about converting to Sanden. I found this one that should connect to current hoses. Don't know anything about them.

https://nostalgicac.com/a6-to-sanden-conversion-kit.html

Click to expand...

FYI, I had looked at this too for my truck. You have to read the ad carefully. It is a Sanden "STYLE" 709 compressor. I was worried about the quality, thus the reason for going with an actual Sanden and custom hoses.

Guys It doesn't matter if your taking the A6 compressor or another unit for an entirely different car, there seem to be problems with no name and off brand rebuilt units not lasting. OP at the shop we use the AC Delco reman units and they have been very good to us. If you decide to get one of the aluminum ones I'd stick will well known brands only I think 4 seasons is ok. One good thing about the A/C systems being high compacity for cooling on our trucks is that they take the retro-fit to R-134A really well. To those having issues with the A6 if your buying a good quality rebuild unit such as AC Delco be sure your using enough oil. If your not sure if your adding enough oil your better off with a little to much than not enough. The primary reason a compressor makes noise is not enough oil, they starve for oil then lock up, or blow out. Make sure your fan clutch is working, if it's not the high side especially in a retro-fitted system will shoot sky high at idle, this creates a ton of heat in the compressor and will kill it over a short time. I'd hate to see you guys spend a ton of money to convert to another compressor just to continue to have problems.

One in my 71 elco leaks enough to need a charge once a year. R12 is expensive to fill it once a year, so I stopped refilling it for now. Need to revisit it again as temperatures go up.

75gmck25 said:

Rebuilt A6’s are incredibly heavy, and often quite unreliable. I went through two before I switched to a Vintage Air Sanden and had new lines made.

The most frequently used direct A6 replacement seems to be the Pro6Ten, and it is supposed to be an exact replacement for the old A6. It should fit the brackets, and the fittings for the lines are the same.

Are you also doing an R134 conversion at the same time? Most new compressors use PAG oil, so you will need to flush the system and replace the accumulator, replace the orifice tube ( and maybe use a Ford blue orifice), and use the new green O-rings. It’s all fairly simple work, but it takes time.

Bruce

Click to expand...

Yep doing all that. Probably going to put a new condensor in as well...maybe not cause I'm lazy and don't want to pull that stuff and if it needs more cooling capacity I may pull it back down and go with a micro tube 134 version.

I think all of not most prongs are changed from before when I filled it. Did a new accumulator then and office but will replace again. I went with ester oil since it's compatible with both and in ase all residue wasn't out. But this time I am going to flush whatever is not replaced.

This is far from my first foray into AC work, not even the first thing that I have swapped from 12 to 134.

Error post

Charlie said:

I have gone thru about 4 A6 compressors and now have one that has worked well for about 2 years. If the current one goes out, I am thinking about converting to Sanden. I found this one that should connect to current hoses. Don't know anything about them.

https://nostalgicac.com/a6-to-sanden-conversion-kit.html

Click to expand...

That's pretty cool, I will highly consider that as an option.

Craig 85 said:

FYI, I had looked at this too for my truck. You have to read the ad carefully. It is a Sanden "STYLE" 709 compressor. I was worried about the quality, thus the reason for going with an actual Sanden and custom hoses.

Click to expand...

I wondered that myself...thinking it looked like a white box compressor.

SirRobyn0 said:

Guys It doesn't matter if your taking the A6 compressor or another unit for an entirely different car, there seem to be problems with no name and off brand rebuilt units not lasting. OP at the shop we use the AC Delco reman units and they have been very good to us. If you decide to get one of the aluminum ones I'd stick will well known brands only I think 4 seasons is ok. One good thing about the A/C systems being high compacity for cooling on our trucks is that they take the retro-fit to R-134A really well. To those having issues with the A6 if your buying a good quality rebuild unit such as AC Delco be sure your using enough oil. If your not sure if your adding enough oil your better off with a little to much than not enough. The primary reason a compressor makes noise is not enough oil, they starve for oil then lock up, or blow out. Make sure your fan clutch is working, if it's not the high side especially in a retro-fitted system will shoot sky high at idle, this creates a ton of heat in the compressor and will kill it over a short time. I'd hate to see you guys spend a ton of money to convert to another compressor just to continue to have problems.

Click to expand...

This is the kind of info I was looking for and what I had suspected. If I went reman I was only going to use AC Delco hoping the quality to be better than the random white box reman companies.

Also
I did know about the front Seal designed to leak to lubricate it. It won't be a problem to throw a small amount of a can in every year and every other year useing a partial oil charge can.

Delphi V5 compressor. I have one or two laying around