Ac compressor cleaning, 1964 deVille convertible

[Tim Broyan]

I've replaced-repaired, cleaned and tested the complete system so I'm confident that everything will work as new. I vacuum tested the system first to see first if the installed system had any leaks. The controls moved the trap doors and turned the fan on as stated in the Tim's AC manual. My issue is that after flushing all of the components that are required to be cleaned or replaced, the only thing left to flush or make sure that it is in good condition (no contaminants) is the compressor itself. It came from a system that was closed to the best of my knowledge but had no refrigerant in the system and had just a little oil in it, so I think it had a severe leak somewhere in the system. I can turn the compressor by hand and can feel the internal workings seem to be just fine, but I'd like to know what is required to make sure the compressor itself has no contaminants in it. 

At this point all I need to do is add the required oil and gas up the AC unit, but I'd hate to have to go through all of the work flushing the system and the cost of replacing the items required to make the system serviceable.

Has anyone dealt with this before?

[Mark S Anderson]

the compressor has very little capacity to hold in contaminants other than in the crankcase, so that's where you should be focused. Assuming that you will be charging with R134a, the main problem is that the original mineral oil is not capable of dissolving in R134a (non miscible is the term), so all of the original oil must be removed to prevent liquid 'slugging' in the suction side.  You should drain the oil, filll it with solvent flush, drain it again, then fill it with ester oil (which sorta kinda mixes with mineral oil) turn the compressor by hand to mix, and drain that out.  then you should be able to refill it with oil and charge the system. 
After a small run, since it was open (a system with a leak is considered open once it's empty), then i'd empty and recharge the system to assure that all the mineral oil is gone.

if you have r12, simply change the oil and charge.  that oil is bullet proof.  just make sure you get mineral oil and not pag or ester. 

[Tim Broyan]

I do have r12 and mineral oil. Thanks for the response. I haven't found anything anywhere that helped me and I was hesitant to just bul into what ai thought would work.

I've had several cads of this vintage but many years in the past and never needed to do anything to the AC system. Prices are higher and too many aftermarket systems that are not only more expensive but don't get appreciately colder than the original unit. I'm in the northwest part of Washington so we don't get 100+ days of heat very often and when that happens, I just put my little boat i n the water and go have a beer in the Islands till it cools off a bit.

Thanks again for the help.

[Mack]

I got my AC back working too and gotta refill with R12… where did you find mineral oil? 

[Tim Broyan]

Rock auto