Mrmerlin

How much oil should be put back into the compressor for an 86 expansion valve and receiver drier and all O rings in the lines as well as both of the lines from the compressor are being replaced.
I looked in the WSM and it said something along the lines of 12 OZ thats seems like a whole lot
I have mineral oil and plan on using R 12 for the refill

ammonman

Page 87-103 of the WSM gives the following approximate distribution of the total oil in the system for particular components:

Compressor=40%
Evaporator=35%
Condenser=15%
Fluid Tank (dryer) and lines=10%

The WSM recommends pouring the necessary percentage of the total oil charge based on the component replaced directly into the new component. Haven't found the total oil capacity in the manual but it is sometimes on the under hood sticker that shows the total refrigerant charge.

Hope this helps.

Mike

WallyP

As Mike says, the oil in the system is distributed thruout. The oil travels with the refrigerant, and the numbers given are the approximate amount in the specified components at any given time.

The total quantity of oil for a system with the 6E171 compressor is 260-300 c.c.

The amount that you should add is the amount that was removed. Did you drain the compressor? Did you flush the system?

If not, I would add about 30 c.c.'s and call it good.

Mrmerlin

I flushed each component and drained the compressor and am adding new compressor lines , a new drier, and ex valve and all new O rings on the 86.
no rear air

dr bob

Stan-

The 12oz number is good. Wally's suggestion on replacing the quantity of oil that came out is good, looking at compressor replacement. It considers how much has circulated and is coating the walls of the hoses, heat exchangers and drier. Since you flushed those components, replaced the drier, and drained and oil-flushed the compressor, you should look at the system capacity as a whole, minus what's hung in the compressor after the oil-flush. WSM suggests 350cc/12oz for a completely empty system, so that would be your target. Subtract out what you think might be in the compressor now after the oil flush, say 25cc or 1oz. Put 8oz in the compressor, and either pour the balance into a hose or vacuum it into the high-side port to the drier after your initial gross-leak test under vacuum. Then re-evacuate for a while, you know the drill.

You mention going back with mineral oil. Consider using POE instead. It's compatible with R-12 and your new drier dessicant, is a better lubricant, and leaves you the option to swap to R-134a at any time without opening the system again at all. Just add charge port adapters, recover the old R-12, evacuate, and charge with R-134a.

Ed Scherer

Related question: if you have an unknown quantity of oil in your A/C system and want to start off with a clean slate again, do you have to flush (with appropriate solvent) the system (lines, condenser, evaporator) to get all existing oil out or can you just try to blow it out with dry air or nitrogen?

I'd worry that flushing (when doing the lines) with solvent would dissolve some of the oil on the o-rings that helped maintain good seals.

JHowell37

You're not supposed to "flush" compressors, but if it were my car, I'd flush the evaporator and the condenser, and I'd drain as much as possible from the compressor and then I'd start over from the beginning. Although a PITA, you can flush the evaporator in the car. The condenser is no big deal to remove. After draining the compressor oil, I'd add some fresh oil of the variety you plan to use, turn the compressor over a few times to circulate it, and drain it. Then I'd put it back together, vacuum, charge, and go.

You really don't need to get all precise and distribute oil everywhere. It will sort itself out in a few seconds.

Mrmerlin

Ok so i am planning to use the mineral oil thanks for the suggestion DrBob .
but I already bought the oil.
So I flushed out everything and will add the 12OZ back into the compressor minus about 1 oz .

I already added oil to the compressor and spun it a while then drained it again only about 5 oz came out to begin with so I am sure it has been leaking plus I found a few loose connections and a blown suction line and a plugged expansion valve.
I have to find a vacuum pump I dont have one.

The other part of this is that the blow off fitting that screwed into the drier is 1 MM bigger in diameter than the hole in the new part so the blow off valve wont fit.
I left it off,
the end of it appeared to be wet with oil/dye in it.
Any suggestions??
My 88 doesnt have a blow off valve so i was figuring that the valve may not be needed on the 86

Dan87951

Im in the middle of this process right now and the guy from ackits.com recommended 8oz of PAG oil for my AC compressor but im converting to r134a.

WallyP

No system that has been run with R-12 and mineral oil should never have PAG oil. PAG is incompatible with the remnants of mineral oil that you can't get out of the system. POE will work with the remnants of mineral oil.

JHowell37

Can you post a pic, because I've got a '86, and I don't recall seeing a blow off valve on my drier.

Landseer

Is there a blow off valve up near the expansion valve?

Dan87951

Wally I don't know if that directed at me but I never suggested PAG oil for his system!

WallyP

The post wasn't because you suggested PAG for him, but because someone suggest PAG for you. PAG is the oil for systems that have never had mineral oil installed. If your system has had mineral oil installed, you should not use PAG. POE is the oil for systems that contain traces of mineral oil.

Just making sure that was clear to all.

Dan87951

My whole AC system has been gone through. New hi and low pressure hoses (now barrier hoses), new compressor, new receiver/drier, new expansion valve, condenser and the remaining lines have been flushed with "Flush-Safe AC" safe per ackits recommendations. I guess once I get everything put together and installed will see how well ackits recommendation was. Thanks for the input Wally.