This is what the A-6 compressor drain plug is for!

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Rich,
May be rust as the compressor is the only one in the system that will rust. Mineral oil doesn't prevent rust... Try to turn the hub clutch anain. The guts ate strong. If it turns slowly it would seem like a hydraulic lock, but that doesn't seem possible because the oil would drain down into the oil pan. The system would have had way to much oil and would not have cooled very well.
I am thinking rust. Try turning the 9/16 nut in the center of the hub and see if it will turn. If you think you are putting to much on the nut then take a belt and wrap it around the rubber on the hub clutch and try it that way. the belt off your pants will do it also.
Feel free to call me. (760)831-2095


Dom

[Richard M.]

Re: This is what the A-6 compressor drain plug is for!

Rich,
May be rust as the compressor is the only one in the system that will rust. Mineral oil doesn't prevent rust... Try to turn the hub clutch anain. The guts ate strong. If it turns slowly it would seem like a hydraulic lock, but that doesn't seem possible because the oil would drain down into the oil pan. The system would have had way to much oil and would not have cooled very well.
I am thinking rust. Try turning the 9/16 nut in the center of the hub and see if it will turn. If you think you are putting to much on the nut then take a belt and wrap it around the rubber on the hub clutch and try it that way. the belt off your pants will do it also.
Feel free to call me. (760)831-2095


Dom

Dom, Thanks for the info and call offer. I'll try the wrench on the hub and I also have a strap wrench. I'll let you know after I try it in the morning.

Rich

[Richard M.]

Re: This is what the A-6 compressor drain plug is for!

Dom it moved with a 9/16 socket. Still a bit tight and not sure how loose it should be at rest. Will run engine to see if it still hangs up.

Rich

[Larry M.]

Re: This is what the A-6 compressor drain plug is for!

Dom it moved with a 9/16 socket. Still a bit tight and not sure how loose it should be at rest. Will run engine to see if it still hangs up.

Rich

At rest (pulley held tight by compressor/fan belt) the hub can be easily rotated by hand. You should rotate clockwise as viewed from front of car....as per normal rotation. Some compression during rotation can be felt, but it is not very much do to slow shaft rotation.

Have a friend that went thru two AD DELCO rebuilt compressors when getting his AC system operational. Both would rotate by hand when cold, but both also locked up the shaft after about 2-5 minutes of operation. Belt would either smoke or come off the pulley. These were new/rebuilt units purchased from GM dealer. My friend was the Chevy Dealership Parts Counter Man.......so no issues returning.

Solved problem by going to the new ALMA/APCO A6 compressor for the third one. Never did determine why the ACDELCO ones would seize......although both were returned for credit as mentioned above.

But if your A6 ran previously and does not now, I do not know what could be the cause.....if the refrigeration side always remained charged up.

Larry

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Hi Dom, Old A6 thread resurrected...

What would cause the A6 compressor to seize when I turned on the AC? R12 system serviced about 5 years ago. I thought it was running ok but saw smoke from the hub/clutch so I shut it off right away. Car sat inside but not run since June 2017 but AC cold then.

Should I try to wrench the hub to free it up or am I dreaming? I suppose the clutch is now junk too.

Thanks,
Rich

Rich,
That's a good sign. They are stiff when pressure equalizes. Make sure a business card fits in the gap between the hub clutch and the pulley. I have found that the pulley bearing grease will separate and turn to oil. It will leak out just like it does in a grease gun when it sits for a long time. It will seem like a front seal leak and also cause the metal to metal clutch to slip. If you find oil on the paper you slide in the gap then spray clean it out and if that were a problem it would help. The swash plate has 6 brass slides that will stick somewhat like the clutch on the car when it sits, (Indifference in metal). It doesn't do much to hurt the operation of the swash plate. The clearance is .0005 and that's a tight fit. It can be as tight as .0003, and those as you know are tenths of a thousands.
It is not uncommon when I get one in that it won't turn and has to be turned by force to break it loose. Forcing will not hurt it as there is nothing that will twist, or any connecting rods to bend.

Dom

[Mark E.]

Re: This is what the A-6 compressor drain plug is for!

I just feel better knowing we have Dom as our club's A6 man.

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Mark,
Try to do my best! Thanks for that, because I love helping the members and does not even pay rent on the shop, but the trust in payment was 100%. There is not a bad guy on the forum/club...
It's a pleasure to be a member and have a part of my work on these cars.

Dom

[Richard M.]

Re: This is what the A-6 compressor drain plug is for!

Rich,
That's a good sign. They are stiff when pressure equalizes. Make sure a business card fits in the gap between the hub clutch and the pulley. I have found that the pulley bearing grease will separate and turn to oil. It will leak out just like it does in a grease gun when it sits for a long time. It will seem like a front seal leak and also cause the metal to metal clutch to slip. If you find oil on the paper you slide in the gap then spray clean it out and if that were a problem it would help. The swash plate has 6 brass slides that will stick somewhat like the clutch on the car when it sits, (Indifference in metal). It doesn't do much to hurt the operation of the swash plate. The clearance is .0005 and that's a tight fit. It can be as tight as .0003, and those as you know are tenths of a thousands.
It is not uncommon when I get one in that it won't turn and has to be turned by force to break it loose. Forcing will not hurt it as there is nothing that will twist, or any connecting rods to bend.

Dom

At rest (pulley held tight by compressor/fan belt) the hub can be easily rotated by hand. You should rotate clockwise as viewed from front of car....as per normal rotation. Some compression during rotation can be felt, but it is not very much do to slow shaft rotation.

Have a friend that went thru two AD DELCO rebuilt compressors when getting his AC system operational. Both would rotate by hand when cold, but both also locked up the shaft after about 2-5 minutes of operation. Belt would either smoke or come off the pulley. These were new/rebuilt units purchased from GM dealer. My friend was the Chevy Dealership Parts Counter Man.......so no issues returning.

Solved problem by going to the new ALMA/APCO A6 compressor for the third one. Never did determine why the ACDELCO ones would seize......although both were returned for credit as mentioned above.

But if your A6 ran previously and does not now, I do not know what could be the cause.....if the refrigeration side always remained charged up.

Larry

Success! Had a busy day on some other issues but finally ran it after wrenching it to free it up, and it now runs from the engine without slippage. But it appears that the R12 is low/gone as I get no cooling. This may explain why it seized up from sitting so long. This system doesn't have a low pressure switch. I'll have to get it to a friends AC shop to pull a vacuum and charge. I have plenty of R12 leftover from the last recharge about 5 years ago.

Dom, I didn't see your 3pm post until just now but I'll make those checks of the clearances tomorrow and report back.

Larry, After running the engine a while after shutdown I can move it easily by hand now.

Thanks,
Rich

[Mark E.]

Re: This is what the A-6 compressor drain plug is for!

Happy endings are good to hear. Now let's hope there isn't a leak that requires tearing the system apart.

[Richard M.]

Re: This is what the A-6 compressor drain plug is for!

Update...

Dom, You were right on the money. I hadn't thought of that. Both sides just as pictured with evidence glaring.
HubClutchOilTest.jpg

I'm thinking of removing the clutch to do a good cleaning of both surfaces. I forget but I might then have access to the felt seal and wash that in solvent too. I replaced the bearing when I restored the car, but that was in 2001. Maybe I can check and clean the outer bearing surface seal area a bit too.

I also will use your method and try to check the oil level, especially since I get no cooling now. I spoke to another friend near home last night and he has the AC test equipment too so now I have 2 places I could trust for testing and recharging. He said he could add some R134A in it to check, and if ok suck it back out then charge with R12. I didn't know that could be done. Do you concur?

Mark, Hopefully it'll pull a vacuum and hold and the system is ok. I'd not look forward to pulling the system apart..... again. Was much easier when I had the car apart under restoration. Agree with you that Dom is such a great help and so appreciative of his guidance with this.

More Later....
Rich

[John F.]

Re: This is what the A-6 compressor drain plug is for!

Dom

Here's a Robinair A-6 dipstick that I got off eBay; no level markings on it.

Back in the '90s, when I had visions of doing work on my compressor(s), I acquired enough of the Robinair tools to at least R & R clutch, pulley, bearing, seal, etc.


[ATTACH=CONFIG]59765[/ATTACH]

Grandkids can also use that tool to blow bubbles, when not being used in the garage.

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Update...

Dom, You were right on the money. I hadn't thought of that. Both sides just as pictured with evidence glaring.
[ATTACH=CONFIG]101027[/ATTACH]

I'm thinking of removing the clutch to do a good cleaning of both surfaces. I forget but I might then have access to the felt seal and wash that in solvent too. I replaced the bearing when I restored the car, but that was in 2001. Maybe I can check and clean the outer bearing surface seal area a bit too.

I also will use your method and try to check the oil level, especially since I get no cooling now. I spoke to another friend near home last night and he has the AC test equipment too so now I have 2 places I could trust for testing and recharging. He said he could add some R134A in it to check, and if ok suck it back out then charge with R12. I didn't know that could be done. Do you concur?

Mark, Hopefully it'll pull a vacuum and hold and the system is ok. I'd not look forward to pulling the system apart..... again. Was much easier when I had the car apart under restoration. Agree with you that Dom is such a great help and so appreciative of his guidance with this.

More Later....
Rich

Rich,
One day my friends wife came over to the shop to pick him up and her air was out and she was pink from the heat with another 40 min to drive. She had a BMW with R-12. All we had was R-134. Her husband said do anything, so I gave it som 134 over the R-12 and it cooled nicely. I told him that he would be facing a problem. Car cooled for over 2 years and was cooling when they traded it in.

Dom

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Grandkids can also use that tool to blow bubbles, when not being used in the garage.

Wayne,
That's neat, never knew they had that.

Dom

[Domenic T.]

Re: This is what the A-6 compressor drain plug is for!

Rich,
One day my friends wife came over to the shop to pick him up and her air was out and she was pink from the heat with another 40 min to drive. She had a BMW with R-12. All we had was R-134. Her husband said do anything, so I gave it som 134 over the R-12 and it cooled nicely. I told him that he would be facing a problem. Car cooled for over 2 years and was cooling when they traded it in.

Dom

Rich,
Don't do it, remove the clutch. Spacing gets nasty when a bit of brake cleaner will get you where you need to go.. Works or not? If the system works then the hell with the clutch as it wears evenly, grove to grove. If comp leaks then that's different. Also is it grease or comp oil?

Dom

[Richard M.]

Re: This is what the A-6 compressor drain plug is for!

Rich,
Don't do it, remove the clutch. Spacing gets nasty when a bit of brake cleaner will get you where you need to go.. Works or not? If the system works then the hell with the clutch as it wears evenly, grove to grove. If comp leaks then that's different. Also is it grease or comp oil?

Dom

Dom are you saying NOT to remove clutch? I couldn't get to work on it today.

Not sure if system works yet as I get no cool air from vents. Next week I'll try to get it tested and serviced. Great info about the BMW R134A temporary fix.

Not sure if it's grease or comp oil. Is there a way to know with some test of some kind, or color? It quite black on that business card I used to check it with.

Thanks
Rich