Motorcraft YN-12-D PAG Oil single or double end capped?

[gdk771]

I am replacing the accumulator on my 96 Ranger. I obtained some Motorcraft YN-12-D PAG Oil for it which is supposed to be the correct oil for my AC system. Does anyone know if this is single or double end capped? I tried to contact Ford and they had no idea. I guess if the system was originally charged with single end capped oil it is a moot point but I am trying to reduce the chance of moisture absorption using double end capped oil, especially if that is what it came with originally. The system has never been opened up for repairs prior to this so I know it has the original oil in it. It says on the can meets specification WSH-M1C231-B but I can't find out anything about that either. I saw in another table that this is just PAG 46 oil but I can't find out anything about single or double end capped being used originally at the factory. I am enclosing a picture of the can also. Ford seems to like to package things in weird sizes like 7 oz for some reason.

 

[adsm08]

What do you mean "single or double end capped"?

There is a little metal plug under the cap of the bottle if that is what you are asking.

 

[fastpakr]

What do you mean "single or double end capped"?

There is a little metal plug under the cap of the bottle if that is what you are asking.

Apparently 'double end capped' means the molecules are stable and less likely to bond with moisture in the oil. I think most decent brands of PAG 46 will be, and certainly Motorcraft branded PAG oil ought to be.

 

[adsm08]

Apparently 'double end capped' means the molecules are stable and less likely to bond with moisture in the oil. I think most decent brands of PAG 46 will be, and certainly Motorcraft branded PAG oil ought to be.

I hate it when people who understand molecules try to work on cars.

 

[gdk771]

I happened to run across this on the acsource.net forum and it appears that Ford PAG is indeed double capped. Here is an explanation of single vs double end capped from the same forum.....

"The double end capped PAG is a chemical structure term. PAG lubricant is an ether based polymer made from ethylene oxide and propylene oxide. The polymer can be started (initiated) from water or an alcohol. If it is started from water and no further post polymerization treatment is performed, you will make a PAG diol (no end capping at all, both ends of the polymer are alcohols). The diols are less stable and take up more water than other types of PAG.

If you start the PAG polymer from an alcohol (butanol for example) and do no post polymerization processing, you will get a single end capped PAG (one end is the terminal alcohol and one is the butane / alkyl end of the butanol initiator). The GM PAG is single end capped.

If you take a single end capped PAG and react it with methyl chloride, you can 'cap' the terminal alcohol and make a double end capped PAG, one with no alcohol groups on the ends of the polymer chain. This is the most stable and least water uptaking PAG available. It is also the most expensive due to the extra processing to cap the terminal alcohol group. The Ford PAG is double end capped."