apwatson50

Thanks for the additional information.

I've done a little reading and it appears that ester oil is compatible with the original mineral oil, so I will be using ester oil. However I think i've decided that I should remove the compressor and drain as much oil out as I can and refill with the ester oil. So i'll just have to check the FSM for the amount of oil to put in the compressor.

If I do drain the compressor and refill with the correct amount of oil, should I still put oil into the condenser? I have installed it, but its only 4 bolts to remove, haven't installed the grill.

Thanks, Aaron

searcher

I don't know about the compatibility issue between the 2 oils. What happens when you add ester oil to the system with 134a is that the 134a picks up the ester oil and circulates it for lubing the compressor. All the mineral oil for the R-12 settles out and usually sits in the condenser, dryer, evaporator, and to a lesser extent in the compressor. Mineral oil will never mix with ester oil. The question is not if the 2 oils are compatible but rather which oil is compatible with propane as a refrigerant. Since your system was designed for mineral oil I would think that if it is compatible then it should be your choice. I am thinking that mineral refrigeration oil is compatible with propane because I seem to remember that propane can be used to top off an R-12 system.

searcher

A little info on this subject: Propane for AC is sold as R290. Mineral oil is the correct lubricant. A system charged with propane will use 40% less horsepower than one charged with 134a (easier to compress) thereby causing less wear on the compressor http://209.85.165.104/search?q=cache...ient=firefox-a . The flash point of propane is actually higher than 134a making it less of a hazard. 134a creates a poisonous gas when exposed to heat. This happens when servicing a hot engine. Propane is less hazardous because it dissipates quickly.

As for adding filters, my only experience with them was the last time I recharged my truck. I changed the compressor and dryer as well as the h valve, I installed both a high side and low side filter from advance auto parts. They were a nightmare to keep from leaking and the system never worked right until I removed the filters, I had to buy new hoses because of cutting to install the filters. I cut the filters open when I removed them and found no trash, System has worked flawlessly for a year now.

apwatson50

Thanks searcher, thats some good info.

So mineral oil will be carried by propane, which means I don't need to add any r134 or any other oil, other than a couple ounces of mineral oil?

searcher

Only leaves one question; Is the propane you buy off the shelf at Home Depot pure enough to charge with. The Ford guys use it. R290 is actually a mix of propane, butane, and 1% argon. I think purity might be the only problem but other people are using it.

apwatson50

Well I guess if its good enough for a ford then its good enough for a dodge. haha