I'm looking for the appropriate AC system mineral oil for the factory AC in my 78Z.  The FSM call for SUNISO 5GS.  I've spent about the last 2 hours scouring the internet for this product, but, other than obscure listings from questionable (or expensive) overseas websites I've not had any luck finding it.  I'm wondering if there is a suitable substitute product that i might purchase that isn't too expensive, will lubricate the system appropriately, and is available in, say, a 1 quart to 1 gallon size.

Thank you for any ideas you might pass along.

Quart to a gallon? that's a lot of oil. anyway I am pretty sure you just need to use mineral oil designed for use with R12. this assume you have a stock system that has never been switched over to R-134 (often done considering the age of these cars, a common practice was to convert after R-12 was no longer used sometime in the mid 1990's).

So make sure you know what you have before adding oils or refrigerents as the two types (12 and 134) of freons and oils are not compatible. You may want to do some research on ester oils if you are unsure and just want to add oil due to a leak out of oil. Some details on what your are doing would help (conversion, full recharge, repair, replacement of parts etc....). 

Example

https://shop.advanceautoparts.com/p/factory-air-1-quart-bottle-mineral-r12-w-o-dye-w-o-parrafin-sold-by-each-59000/20891190-p?product_channel=local&store=9308&adtype=pla&product_channel=local&store_code=9308&gclid=CjwKCAjw_LL2BRAkEiwAv2Y3SfO9u8ORqhQYzALS54Zgp6sql9jkTBwAa2E_aCQFCGzjXSt3Hi9Z8RoCrfoQAvD_BwE&gclsrc=aw.ds

Thanks Dave

I don't actually need a gallon...it was just that after my earlier internet search, it seemed like a lot of the industrial websites were only selling it in quantities even larger that that.  I'm sure a quart would be fine.

Im the second owner of the car and bought it when it was 2 years old (1980) so the system has never been converted to R-134.  If you recall, I'm the same guy who posted a pic of my leaking condenser on this forum back in January (you responded to that post).  I'm just now starting to put everything back together after working on my engine bay over the last 6 months. As I gather everything necessary to try and get the AC system working again, I just wanted to make sure I had the correct oil to service the AC...and I wasn't sure just how important it was to use the FSM recommended brand.  From your response I gather it's not that important, and I'll just go with something similar to what you recommended.  Thanks!

I presume A/C mineral oil is A/C mineral oil, so yes I would go with that. Did you source a new condenser? IIRC there was a correct fitment one out there new, expensive but fitment means not having to make mods to get it to work. So you are staying with R-12, good move I have been very happy with my R-12 system. Main thing of course is to make sure you pull a good vacuum and let it set for a while to boil off any water. Check the filter at the engine side firewall connection high side of the evap to make sure its not gunked up. And of course a new drier. Hopefully you have a easy to source one (unlike the 75 model).

Couple things.  First the good.  The little filter at the firewall connection is pristine.  Glad to see that. And I have a lot of R-12 to work with.

The condenser and drier problems are not yet solved.  Do you recall the source for the new expensive condenser you spoke of?  I have searched online, but you know how that goes.  hit and miss.  surf for hours.  frustration. 

I'm leaning toward buying a used condenser from the "Z man of washington".  His name is Oliver and his business is within a reasonable driving distance from my home.  I know it's a gamble, but his prices are reasonable and i will get it tested before installing it.  After all...i might even get lucky and get a perfectly serviceable one for my exact year model (78).

As for the drier...i'm convinced that finding an OE one is not gonna happen.  That means finding an aftermarket one, preferably with the connection for the high pressure switch, which seems unlikely as well.  So that means that the most likely solution will involve refabricating the copper lines to/from the drier to make an aftermarket one work.

So that's where I'm at.  Fortunately, AC is more of a luxury where I live and I'm willing to "chew" on this problem for a while and drive the car without AC in the meantime.

Thanks again for all your insight.

 

http://autoacsolutions.com/products/condensers/1974-1975-1976-1977-1978-datsun-nissan-240z-260z-280z-a-c-condenser/

I would stay away from used condensers.

There are aftermarket generic fit types but they would require new hoses, figuring out mounting etc.. if you value your time I would go with a direct fit.

 

The drier should be no problem IIRC yours is a simple top fitting type, unlike my unicorn mid inlet top outlet type. Any decent AC shop near you should be able to match up what you have as far as fitment.

Its brutal here, 90f today and that's low for the next 5 months, AC is a must have in the SE.

You said you had a lot of R12 to work with. I still use R12 in my 75. Where did you get the source of R12?

 

yeah...i suppose I should qualify what "a lot" is....several years ago a guy who lived near me was advertising cans of R-12 for sale on Craigslist.  Now he had A Lot.   like cases of the stuff...I prolly bought about 10 cans from him...maybe have 5 or 6 left at this point.  I would recommend keeping an eye out on CL, ebay, and word of mouth...even things like yard sales.  If you stay diligent about it I would bet you'll eventually score some.