A/C compressor

Okiedokie · July 16, 2020, 09:41:36 AM

In order to use the factory front accessory drive [1986] on the 302 in my 55 Ford I am using a reman compressor from Murray/Four Seasons with my Vintage Air system. The compressor came with a label stating that it is charged with 3 oz. of Pag 46. This compressor from the factory when it as R12 held 13 oz. of mineral oil. I have emailed Four Seasons with the question is that the complete capacity of the compressor. I know that the Sanden compressor in my 40 holds 7 oz. of oil. Can someone with more knowledge than I provide any input?

kb426 · July 16, 2020, 10:18:44 PM

I did a little research because I was curious. I think the most recent units I installed took 7 ozs. In reading, one description said that there was a minimal amount of oil to prevent rusting of the compressor. Another showed a tag on the unit with the correct amount for it. I'm guessing there's no tag or you wouldn't have asked. I found this manual that has a formula to figure oil capacity out.
http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf

Okiedokie · July 16, 2020, 11:00:52 PM

Thanks for your reply. The only tag says that it has 3 oz. in the compressor. I know that the Sanden in my 40 holds 7 oz. but this is a Ford Factory unit. I sent Murray an email asking the question but they have not responded.

kb426 · July 17, 2020, 08:13:17 AM

If if helps, I put 7 in the 4.6 Ford out of a crown vic with the factory compressor. If you get too much, you can loose some cooling efficiency. I used Vintage Air guidelines on most of what I've done because I'm no expert.

enjenjo · July 17, 2020, 08:31:18 AM

Is this an R12 system or R134?. Are you doing a conversion from one to the other? On an existing system the rule of thumb is one ounce per component replaced.

Okiedokie · July 17, 2020, 09:45:42 AM

134 on a new Vintage Air system. these compressors when new were R12 but the remans are 134. Everything is new.

enjenjo · July 17, 2020, 07:42:55 PM

If you have 3 oz in the compressor, I would add 4 more for the rest of the components if all of it is new.

Okiedokie · July 18, 2020, 08:18:29 AM

Thanks enjenjo, your advice is always good.

Okiedokie · July 20, 2020, 02:42:06 PM

An update. I spoke with a Vintage Air company tech this morning. He said that the system needs only what the compressor manufacturer specifies. The small Sandens they sell are charged with 4.5 oz and the larger ones are 7.2 oz. No additional oil need be added. So I will not add any more to the Murray reman Ford compressor. Thanks for all the input.