Oil changing on hermetic compressors.

[alexdouglas1969]

Hi folks

Is there any method of oil addition / removal on hermetic systems, I understand not, but I have a feeling some of you may know otherwise.

Thanks.

[Peter_1]

Why you should want to remove or add oil?
You can only remove by tilting it upside down after removing the tubes. Adding is much easier, just insert the oil in very small quantities in the suction.

[lana]

Hi there,
If you want to change the oil to synthetic one DO NOT do it.
Thats the whole idea of hermetic no to do any change on it (in my opinion anyway ).
Cheers

[monkey spanners]

Also if its got a rotalock suction valve you can suck the oil out through a thin tube. Make a vacuum tank out of an old disposeable bottle, braze another tap onto the top of the bottle, pull a vacuum on it from the original tap, fit tube onto new tap, fit thin tube onto tap, lower tube into compressor, open tap and suck out the oil. Or get a oil syringe from a tool shop/machine mart. For thin flexible hose try model car fuel hose (silicone)

Cheers Jon

[The MG Pony]

I have don it many times with my little ones. Simply dump out the old oil via suction line or service tube, then flush with 99% Isopropyle alcohol to clean out gunk and residue, warm up and blow nitrogen through to dry off the alcohol, vac it for 1 Hour while warm then toss in the new oil by pulling a vac on the discharge side and sucking the oil in via suction side.

Not one compressor has failed or leaked with that method and dam do they sound allot healthier after wards!

[jsimon]

i did hear on the grape vine a firm used to drill a small hole in the base of the comp allow it to drain overnight and refill in the morning,

[Rob S]

Used to change the oil on all those old r12 and r502 units to TD150 all the time. When switching over to a retrofit gas. Seen some pretty sluggy oil come out of some. Gota love those chunks of goop.

[momo]

Having recently "tried" to do a good study on oils (to give a brief idea on a training course)... oil changes mineral > Synthetic: problems are too great to be worth it for hermetics: old oil residue and % remaining needs to be very little 5% or less so repeated flushes become expensive... Also the insulation on the windings can be affected by different oils and additives, (and bearings) ...
How in any case can you easily identify which oil to put in/refill?

On the mechanical side: hole in the bottom to drain??? how do you seal, brazing with oil - NO way, rubber plug?!!!! or mechanically screw tapped perhaps ...
I'm sure someone around knows how developing nation experts manage to split open and reseal hermetics (like a coconut?) - current course colleagues from Colombia and the African coast brag about it - but don't tell the secret.

The MG Pony mentioned not that long ago the near total secrecy of the art of lubrication, ultimately I concluded: "what the manufacturer recommends" - if you kept the service manual - since it becomes extremely complicated with types and additives etc...
Any readable studies on it available?

[The MG Pony]

I'll soon be having fun replacing the oil in two units with the same, Scroll I'm not sure how to do but the recip will be a snap!