oil

[Mel S.]

How many ounces of oil goes into the AC compressor for a 1966 with factory air (C 60)

[David M.]

Re: oil

Taken from my 68 Motors manual. I cant get the pic any larger. Hopefully someone more tech savvy can assist.

FYI....R12 systems use 500 viscosity mineral oil. R134A systems use PAG oil. The two are not compatible. If mineral oil is used with R134A, it will not mix with the refrigerant, and the compressor will starve for oil and seize. Fortunately there are solutions. Ester oil is compatible with both PAG and mineral oil. Furthermore, there are additives available that will make the old mineral oil in the system mix with R134A.

https://www.classicautoair.com/

https://www.vintageair.com/

Either will have everything that you need including the correct seals and oil.

[Larry M.]

Re: oil

How many ounces of oil goes into the AC compressor for a 1966 with factory air (C 60)

A new/clean A6 compressor requires 6 oz of oil in the compressor sump.

The total oil requirement for a completely dry AC system is 11 oz, divided as follows: 6 oz for the compressor (as above), 3 oz for the evaporator core, 1 oz for the receiver drier, and 1 oz for the condenser.

The above information is from Secton 1 of the Chevrolet Service Manual for HEATING AND AIR CONDITIONING.

The service manual also indicates that a "repaired" compressor requires 1 additional oz of oil, or 7 oz total for the compressor. I am not certain of the exact reasons for this statement, except perhaps that a new compressor might have a small amount (1 oz) of residual oil already in the internals from the factory assembly process.

If in doubt, split the difference..............ie. 6.5 oz oil

Dom might want to say what quantity he recommends for his rebuilt/restored A6 compressors.

Be certain........as already stated by David.........that the correct TYPE of oil is used for the refrigerant selected. DO NOT MIX the oils.

Larry

[Mel S.]

Re: oil

Thanks i really appreciate the information
Mel

[Domenic T.]

Re: oil

Larry,
Couldn't figure that one out either 6.5 is safe in my book and I think 4oz is the low level that I read somewhere. Strange thing is that most compressors that come with the manifold ports capped off only have a few oz in them, but they usually come in because they leak oil. The oil plug on the side of the pan that is used to drain excess oil out of the system without loosing the charge may be set at about the 6 oz level? That would vary with a loose belt vs a tight belt and left side vs right side mounting if that is used in other model cars.
Getting oil is getting harder to get with the new generation parts guys & gals. usually don't have a choice and in some cases you have to ask to go behind the counter and look at what they have.
I personally think that mineral oil doesn't prevent rust as 99.9% of the compressors are rusted inside, and other than any metal that will rust on the valve side of the system, it is the largest in the system to rust. Here is a pic of a oil that claims it will mix and is compatible with R-12 & R-134. It also claims it reduces corrosion. it lists for about 37.00 a quart and I think I get it for about half that. Other than the rust corrosion there is a bit of corrosion on the aluminum pistons. Sure don't that in the aluminum condenser or evaporator.
I also find rust inside of aircraft engines that use mineral oil. Seems like mineral oil collects moisture. Knowing that it makes it more important to get all the out that is needed for corrosion to start. Can't figure out why they want oil in the drier with the desiccant?

Dom