air conditioning compressor, 66 390hp

[Joe L.]

Re: air conditioning compressor, 66 390hp

Joe, all have been remanufactured. Is that my problem DUTCH

Dutch------


AC Delco usually supplies high quality re-manufactured units. Nevertheless, I ALWAYS prefer NEW, especially for an item like an A/C compressor. In fact, I just recently purchased a compressor for my late father's old 89 Cadillac El Dorado that I still drive every-now-and-then. The whole car probably isn't worth $1,000 but I paid about 500 bucks for a NEW compressor. I don't want to "mess around" with rebuilds on a compressor. For an alternator, a rebuild is ok, for an A/C compressor, no.

[Gary N.]

Re: air conditioning compressor, 66 390hp

I've had the original A-6 on my 66' redone with new seals at least three times by three different "experts" and never have been able to get it to stop slinging oil. I find that if I let it sit for more that a week that it will sling out some oil, but if I use it fairly often that there is very little oil or none at all being slung. I've also found that the compressor seem to be getting a little more noisy with time. It still works fine and cools great. I also loose a little freon over the summer. When I pulled a vaccum on it and let it sit for about 5-6 hours it held the vacuum just fine. I would like to keep the original compressor, but eventially I may have to bit the bullet and buy a new compressor.

[Jack H.]

Re: air conditioning compressor, 66 390hp

Leaks of R12 and leaking refigerant oil can be two different issues... Certainly if the A6 is throwing appreciable amounts of oil from the front seal (the Achilles' Heel of this compressor), that IS a source of refrigerant loss as well.

But, the interconnect hoses aren't 100% bullet proof when it comes to 'perfect' refrigerant retention and they DO have gaskets at interconnect points that are susceptible to age/deterioration. That's one of the reasons that pulling vacuum on a given system is NOT a proof positive credential for seal integrity...

When you pull vacuum, air is invited to invade from the outside in. When the system is filled and operational, you have high pressure inside trying to exit to the low pressure outside. A given gasket/seal may well 'hold' when flexed in one direction but not the opposite...

Last, the Schrader valves should be checked and re-checked for their integrity. Typically, AC mechanics look at the high and low pressure side valve they use to fill the system, but don't look at the 'extra' valve. Expect to find a pair on the A6 manifold as well as another on the Harrison air box near the expansion valve. Check/test ALL of 'em...

Now, while some say a modest amount of leakage can be expected ESPECIALLY on cars that aren't driven/used, that's not always true. I remember being at a local Texaco station about six years ago when one of the mechanics drove in the '68 Buick he'd just inherited from his mother's estate.

It had the factory original A6 on it and to everyone's surprise, the A/C blew cold air when it was fired up and the sight glass in the receiver dryer showed NO bubbles! So, these cars CAN retain R12 despite sitting for long periods of disuse...

[Harry L.]

Re: air conditioning compressor, 66 390hp

After all this oil being discharged,should we be thinking about adding oil to our a/c systems? How do we know the amount of oil that is still in our system/ Too little oil can;t be good! DUTCH

[Tom L.]

Re: air conditioning compressor, 66 390hp

The only way to tell if there is too little oil in the system is to literally pour it out of the compressor which is no small job. Unless the amount of oil you are seeing from the seal is substantial I wouldn't worry. Don't forget about how much of a mess a vcery small amount of oil will make. Sometimes an eyedroppers worth seems like a quart!

[Kenneth S.]

Re: air conditioning compressor, 66 390hp

Harry:



Ken

[Jack H.]

Re: air conditioning compressor, 66 390hp

Right on! There's no way to know the amount of oil remaining in the various A/C system components without pulling them, draining and measuring.

I believe the Chassis Service Manual's section on A/C cites the proper amount of refrigeration oil for each of the major components (compressor, receiver-dryer, Etc.) and the specs are there to assist mechanics when replacing individual parts with fresh/new ones. So, that's the starting point if one suspects there's been a SUBSTANTIAL loss of refrigeration oil...

[Wayne M.]

Re: air conditioning compressor, 66 390hp

Just thought I'd add this to the discussion: (included in one of the seal kits I have)

"Installation instructions -- All 1962 - 1976 General Motors Compressors

Compressor shaft seals should be replaced only on the basis of actual refrigerant leakage, as determined by test with a propane torch type of leak detector, in good condition. They should NOT be changed because of an oil streak on the hood blanket unless there is an excessive amount of oil in the rest of the engine compartment."

Problem is, as discussed above, to define excessive.

[Larry M.]

Re: air conditioning compressor, 66 390hp

After all this oil being discharged,should we be thinking about adding oil to our a/c systems? How do we know the amount of oil that is still in our system/ Too little oil can;t be good! DUTCH

As others have already said, the only way to know how much oil is still in the AC system is to disassemble everything and measure it all. Then refill with new to the recommended amount. Should be around 12 ounces of 525 viscosity mineral oil.

As an alternative, you can purchase a small can of the correct mineral oil that is sealed under R12 pressure. Can is around 1-2 ounces. You can (SLOWLY) add this one can of oil to your system with the AC system running. Or if you want, add only 1/2 can. The worst case is you wind up with a small overfill that should not cause a problem.

I have personally done this without issue. I had oil leakage, so I knew SOME oil was lost. I guessed about 1 ounce based on what I observed over the span of time the leakage was observed. I added a full can.

I can provide a part number for the pressurized oil can if needed, or just look-up on-line at NAPA etc. This is a fairly common item. Also routinely sold on E-bay. About $5.

Larry

[Harry L.]

Re: air conditioning compressor, 66 390hp

Larry,where and how, do you add this can of oil? DUTCH

[Tom L.]

Re: air conditioning compressor, 66 390hp

I seriously doubt that an oil charge is pressurized with R-12. It has been ILLIGAL to use any CFC's or HCFC's as propellants for years. If a manufacturer wants to us R-12 as a propellant, think about this. R-12's list price is $1781.11 for a 30 lb. cylinder, I'll admit that the trade price is QUITE A BIT lower but it is not reasonable to use R-12 as a refrigerant or propellant. Here is the sourece for my qouote:

http://www.uri.com/is-bin/INTERSHOP.enfinity/WFS/PrcTransaction/en_US/-/USD/ViewCatalog-Browse?CatalogCategoryID=u2sKFgIKnmYAAAEkqcELtLV_&OnlineFlag=1

[Larry M.]

Re: air conditioning compressor, 66 390hp

[QUOTE=Harry Long (49801);454284]Larry,where and how, do you add this can of oil? DUTCH[/QUOTE

On my 1967, I added through the POA valve when the car and AC were running at low idle. Hook up your regular AC manifold gage set, purge the lines of any air, and connect the pressurized can to the yellow fill hose. Then SLOWLY open the suction valve on the gage set (blue hose) with the oil can upside down so that the oil will come out.

Again, add slowly and intermittantly so that you do not slug the compressor with liquid. Add as much as you want/need. Can is very small.

Since you have a 1966 car, you will probably be adding through the STV valve, unless you have another connection on the compressor suction line that is closer to the compressor.

Again, the whole idea is to add very slowly and intermittantly to avoid compressor liquid damage. Should take about 10 minutes to add the 1 ounce can.

Larry

[Larry M.]

Re: air conditioning compressor, 66 390hp

I seriously doubt that an oil charge is pressurized with R-12. It has been ILLIGAL to use any CFC's or HCFC's as propellants for years. If a manufacturer wants to us R-12 as a propellant, think about this. R-12's list price is $1781.11 for a 30 lb. cylinder, I'll admit that the trade price is QUITE A BIT lower but it is not reasonable to use R-12 as a refrigerant or propellant. Here is the sourece for my qouote:
http://www.uri.com/is-bin/INTERSHOP...._&OnlineFlag=1

Lynn:

Interdynamics OC-1 Oil Charge. See attached link.

http://www.id-usa.com/product.asp?CID=43&PID=110

Available many auto parts stores. Also available on E-bay.

Harry may require some help to purchase if he doesn't have a 608/609 license......but these are not difficult to get. I find it hard to imagine that they would require a license for these small cans, but you never know. However, you also need this to (legally) get your R12 supply.



Larry

EDIT: While I see the high $$$$$ for R12 in your article, the "street" rate is around $400-600 for a 30 lb cylinder. Some of this supply at this $$ may be reclaimed, and not virgin. However, properly reclaimed R12 should be just as good.