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Full system rebuild - dealer gave me wrong oil?

AR75TS on Tue October 02, 2007 3:25 PM User is offline

Year: 1988
Make: Alfa Romeo
Model: 75 (Milano in USA)
Engine Size: 2000
Refrigerant Type: R-12
Ambient Temp: n/a
Pressure Low: n/a
Pressure High: n/a
Country of Origin: New Zealand

I have done a full car rebuild on my Alfa Romeo. Engine bay is fully painted, engine overhauled, gearbox etc etc. I had the dash out so the evaporator was pressure tested and I had a new expansion valve fitted. I flushed all hoses and have a new drier to go on. I have fitted a slightly larger condensor off a Fiat.

The car had been running for a year before I went to get the AC filled. Unfortunately in that year the AC pump (Sanden SD-508) seized up so I couldn't turn it by hand. I stripped the pump down and purchased the rebuild kit locally. I also asked for a tin of oil compatible with R-12 (Italian AC isn't the most efficient at the best of times, let alone with R134a).

The agent gave me Robinair Polyol Ester Oil for R-134a, FRIGC and FR-12 A/C systems.

From what I have read here this is NOT the correct oil for R-12? Is that right?

Richard

AR75TS on Tue October 02, 2007 3:31 PM User is offline

Forgot to mention. I am just a home mechanic. However I intend to get the system to the point where all clean and sealed ready for evacuation and filling.

Chick on Tue October 02, 2007 4:54 PM User is offlineView users profile

Ester oil will work with R12, R134a etc..However, you most likely had mineral oil originaly..But you can use the ester..Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

TRB on Tue October 02, 2007 4:56 PM User is offlineView users profile

No that is not what I would suggest if running R12. 500/525 viscosity mineral oil has been the choice for 45 years.

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AR75TS on Tue October 02, 2007 5:23 PM User is offline

Thanks for both of your replies. R12 is now outlawed here too and commercial places now only have R134a. Hence the agent said mineral oil is getting less common and told me the stuff they gave me would work. The label didn't mention R12, hence my pessimism. I don't want to go back and accuse them of giving the wrong oil till I am absolutely clear.

As long as it won't cause trouble! I guess it would allow easier conversion to R134a in the future?

Chick on Tue October 02, 2007 5:32 PM User is offlineView users profile

Mineral oil will not work with R134a, so you will need to use ester.,.Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

iceman2555 on Tue October 02, 2007 10:54 PM User is offlineView users profile

This thing with mineral oil is all over...very few jobbers inventory the stuff....and the major problem with POE...some of them anyway...is moisture absorption....and the weight is a bit light for A6's,R4's,and H series.
Chick your statement of 134a and mineral oil....brings to mind some interesting testing we conducted back in the retro fit craze. Seems we were hearing stories about not needing to change the lube for retro fitting.....something like...'hey, you guys don't know what the s&*t you are talking about....been adding 134a to systems and the compressors work great....' and so forth.
So we decided to play around with some different vehicles...go by a local 'by here...pay here'...hey guys...let me have one of these vehicle for a couple days.....and we will put a new A/C in it for you....or find some willing sucker...opps...individual who works with you...and play with their car.....
Any way....took some R'4's, some H series...some FS10's and installed new compressors...condensers...hoses assemblies....keep the evaps...esp on the Fords....some GM's we installed all new parts....others simply got a good evap flush....141b....the good stuff.....added 3-4 oz of mineral oil to the compressors...no where else...nada.....evac and recharge to OE specs 134a......and the damn things would run and run...cool good...not noisy...just run and run........
So, hey this works sooooo good...lets try some 'rice burners'.......ahhhh....sooo.......learned that a rotary or scroll would lock up in a heart beat.....Denso and Sanden piston types would work.....great......suppose it was the actual 'swiping' action of a rotary or scroll that resulted in the failure. Open the locked up unit...heavy scaring..but darn thing would be full of oil?????.....decided it was the oil returning to the compressor from the discharge line/condenser at shut down.
Had some of these vehicles with over 1000 miles of operation in the summer heat of TX...and it was hot as heck that summer.....and not a single failure.
It was decided that the 134a would not migrate the mineral oil from the compressor....so they remained lube'd.......
The guys in the field had been servicing vehicles that still maintained a set amount of mineral oil in the compressor.....thus the ease of simply adding the 134a to the system.....
This is by NO means a suggestion of how to accomplish a retro....just a moment in history......stay with the accepted procedures......nuff said...

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Test Specimen on Wed October 03, 2007 2:16 PM User is offline

Ice, as I remember, test stands running on mineral oil and R-134a did well at high speeds, but had problems with mineral oil circulation at idle conditions. As long as the test vehicle did not see extended idle times, mineral oil and R-134a seemed to work OK. Taxicabs may be another story. The OEMs had to find a lubricant that would work for all the extreme conditons the vehicles see.

JJM on Wed October 03, 2007 5:44 PM User is offline

I don't see how 500/525 mineral oil could possibly work [successfully] with R-134a on non-sump type compressors considering 500/525 mineral oil is not miscible with R-134a. If the oil migrates from the compressor (like top mounted units), the compressor runs dry.

Joe

When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com


iceman2555 on Wed October 03, 2007 11:33 PM User is offlineView users profile

That was the issue....the mineral lube would not migrate from the compressor.....fixed or variable piston types....we would see movement on rotarys and scrolls...but others would just pump away. Remove the compressor....open it up....and there would be sufficient lube to maintain the compressor.
TS...unfortunately....we were not allowed to utilize the co test stands for our 'test'...some one was concerning about the amount of debris to be produced and the effect on the equipment...so we simply obtained vehicles from willing (?) co employees and other sources....nah...never friends (not any more) and family...
Heck we had access to a very large warehouse full of parts....so what the heck...it was fun....never was intended to be a service procedure. In the end...we returned the vehicles to OE 12 specs..or did a proper retro if they desired.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

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