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[email protected] Thu Jul 29, 2021 7:12 pm

syncro surf wrote:
Skills - do you know of an appropriate solvent?

Thanks

this

https://www.napaonline.com/en/p/TEM419955?cid=paid...aw.ds&

or DURA flush solvent.

problem with brake cleaners is it doesn't flash off quick and you can go out the next day and pour it out.

DURA (now DURA 2) would about boil at room temp. the shit was evil but worked real good.

that is what we used doing retrofits at the dealer and if a customer wouldn't spring for a whole new system if the compressor blew chunks into the system we'd flush it with that stuff

brake clean can work, no doubt but be VERY careful you don't have ANY trace of it in the components. even a small amount will strip the lubricity out of the oil and/or mix and make poo

djkeev Thu Jul 29, 2021 11:20 pm

I'll say it again,
Cause no harm.

https://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf



Dave

djkeev Thu Jul 29, 2021 11:55 pm

And more........

Sanden does not seem concerned about minimal mineral oil being in the compressor when switching to PAG ....... if they are not concerned, you need not worry either.
I'd be trusting Sanden over local wrench turners opinions.

I think your flushing of the compressor with mineral oil has far exceeded anything Sanden recommends or expects one to do.
0.5 oz (15cc) of oil clings inside the compressor when drained and rotated.
If you have any PAG at all still clinging inside after multiple oil changes, it is absolutely minimal.

https://www.sanden.com/objects/retro.pdf

Dave

djkeev Fri Jul 30, 2021 12:31 am

Last thought, add a label to your system letting any future A/C service persons know that they are working on a system filled with mineral oil.
Also put your refrigerant choice on the label.

Dave

[email protected] Fri Jul 30, 2021 7:57 am

djkeev wrote: And more........

Sanden does not seem concerned about minimal mineral oil being in the compressor when switching to PAG ....... if they are not concerned, you need not worry either.
I'd be trusting Sanden over local wrench turners opinions.


sanden also sells compressors, and denies warranty claims.

whatever....he asked for opinions and i gave mine after being a tech for 30+ years now.

if you brought it to me....i spelled out exactly how i would do it. you never know who has done what to these old systems at this stage in the game.

dunno...guess spending more than 1/3 of my life in dealerships i have had "cover you ass" pounded into my head.

some have the "send it" mentality....that line of thought has never worked favorably for me

djkeev Fri Jul 30, 2021 12:33 pm

Or......... Sanden knows more about Automotive Air Conditioning and the lubrication needs of a compressor and how different oils interact with each other more than all of us combined know.

Dave

syncro surf Fri Jul 30, 2021 3:28 pm

Thanks everyone for the very helpful perspectives. The only problem I see with looking at Sanden's advice is that they are talking about small amounts of mineral oil in PAG. It does not necessarily follow that small amounts of PAG in mineral oil will behave the same.

From all my reading about oil from various sites (which involves a lot of reading between the lines) I feel like I probably could "send it" with what I've done and be fine. But it seems like everyone here who has done this has flushed with a solvent. Nobody has spoken up who has actually flushed with just mineral oil successfully. As everything in my system, with the exception of the evaporator is new, I'm not sure I want to be the guinea pig.

Harry Callahan's looking at me "You gotta ask yourself one question - do you feel lucky? Well do you punk?"

djkeev Fri Jul 30, 2021 3:49 pm

Over thinking this you are........
but do what is right for you.

It affects me not.

I'd have refrigerant in by now and enjoying the cold air.

Dave

djkeev Fri Jul 30, 2021 5:00 pm

Take a clear bottle
Put in some PAG and some mineral oil.
Swirl it around
Do they mix or are they like oil and vinegar?
If they mix, there is so little PAG oil left in the compressor it is inconsequential.
If they donít mix, then all bets are off.

Dave

Farf Fri Jul 30, 2021 5:56 pm

The mixing of a trace amount of PAG with mineral oil will not form a gel or sludge. It's more about the type of oil and its ability to mix with the refrigerant (miscibility). Since you are using RedTek you have no issues to concern yourself with.



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