Year: 1995
Make: Chevy
Model: C/K fullsize
Engine Size: 4.3
Refrigerant Type: r-134a
Ambient Temp: too hot
I was helping a friend with his trucks A/C. The accumulator, the condenser and the orifice tube along with a damaged line, have all been replaced. The system now holds a vacuum. The system was open with a damaged line for 3 years before the repairs were made. The system oil has not been addressed.
I was planning to just open a line and add 4-6 ounces of oil. Is this OK???
What would you guys do???
Thanks,
Dan
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1990 5.0 LX Sedan
LT Headers short H-pipe/2 chamber FM w/2.5 pipes
T-5 Z model with 3.73 gear/PowerTrax NoSlip
FMS Aluminum D/S 255-gph-fuel pump
FMS HD Clutch w/Adjustable clutch
Nitto 555 Drag Radial/14 Deg timing/Underdrive Pulleys w/130 Amp G3 alt
Front sway bar pulled/Battery in trunk/Fiberglass Hood
Best Time 13.70 @ 101.0 1.89 60-ft.(w/short belt) Still more there
A/C blows COLD :-)
Since it was open that long, I would flush the system. The PAG oil must be loaded with mositure. Then add back the proper amount of PAG 150 viscosity, or better yet, BVA Auto 100 ester oil and charge it up by weight into the vacuum..Hope this helps..
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Chick
Email: Chick
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Freedoms just another word for nothing left to lose
The full flush is not in the cards at this time.
Is just adding a few ounces really asking for it???
It might be too late, my friend just added 4 ounces to the low side, he's now pulling the system down again.
Should I stop him before he adds the 134?
Dan
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1990 5.0 LX Sedan
LT Headers short H-pipe/2 chamber FM w/2.5 pipes
T-5 Z model with 3.73 gear/PowerTrax NoSlip
FMS Aluminum D/S 255-gph-fuel pump
FMS HD Clutch w/Adjustable clutch
Nitto 555 Drag Radial/14 Deg timing/Underdrive Pulleys w/130 Amp G3 alt
Front sway bar pulled/Battery in trunk/Fiberglass Hood
Best Time 13.70 @ 101.0 1.89 60-ft.(w/short belt) Still more there
A/C blows COLD :-)
I can only advise you what I would do. That is flush the old oil out..If not, you are asking for problems down the road, as any moisture will form an acid with the R134a and eat the system from the inside out....Do it right and you'll do it once...Hope this helps..
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Chick
Email: Chick
---------------------------------------------
Freedoms just another word for nothing left to lose
Thanks for the advice Chick, sorry my friend did not have the time or patience to flush his system. Well keep our fingers crossed.
The A/C is blowing very cold right now. We added about 4 ounces of the oil supplied by chevy. The system was left for about 24 hours at 29.xx of vacuum and the accumulator was changed.
Wont the vacuum and and the new accumulator remove some of the moisture that may have contaminated the oil while the system was open???
Or is that just wishful thinking?
Still new at this stuff. :-)
-------------------------
1990 5.0 LX Sedan
LT Headers short H-pipe/2 chamber FM w/2.5 pipes
T-5 Z model with 3.73 gear/PowerTrax NoSlip
FMS Aluminum D/S 255-gph-fuel pump
FMS HD Clutch w/Adjustable clutch
Nitto 555 Drag Radial/14 Deg timing/Underdrive Pulleys w/130 Amp G3 alt
Front sway bar pulled/Battery in trunk/Fiberglass Hood
Best Time 13.70 @ 101.0 1.89 60-ft.(w/short belt) Still more there
A/C blows COLD :-)
Edited: Tue August 26, 2003 at 5:43 PM by mustangdan302
Moisture will be removed by new descant and a deep vacuum.
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I ran some tests last year and found that water mixed with PAG oil is almost impossible to remove by vacuum, and my vacuum pump is rated at 0.1 Microns.
With mineral oil, the vacuum will pull the water right out and the oil looks good as new.
POE is somewhere in between PAG and mineral.
I cannot comment on whether the desiccant will pull the water out of the PAG or not.
Vacuum will pull free water out of the system other than what's in the the PAG so it still needs to be done, and desiccant will pull the water from the refrigerant after charging if there is any.
Has anybody got info on the action of the desiccant on water laden PAG?
No data but I was under the impression that the PAG/water bond is at the molecular level and I wouldn't expect a desiccant to break that kind of bond... Any chemists aboard?
I'm not a chemist but I do have a similar question....
If after doing a flush there is still some residual solvent would pulling a deep vacuum remove it?
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Best & Thanks;
Marvin
If you take 1 ounce of water and mix it with 1 ounce of PAG, the mixture heats up quite a bit indicating that there is a exothermic chemical reaction taking place.
When I did that last year at about 85-90F ambient, the mixture heated up to over 105F. I was quite surprised when I felt the container heat up.
Yes, a chemist needs to weigh in here on the action of PAG with moisture in it and what, if anything, the desiccant can do about it.
Marvin, I believe that 100% mineral spirits and lacquer thinner will be removed by evacuating. They are the only flush materials I use. Don't know about the others that are on the market.
Thanks Mitch - I do use 100% mineral spirits and get as much out as possible (probably 99%) but I was wondering. From the results I've been getting since switching to Mineral Spirits it must be all gone :-)
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Best & Thanks;
Marvin
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