Automotive Air Conditioning Information Forum (Archives)

wptski on Sun August 04, 2013 9:36 AM

I was reading a post in a Ford Escape Forum where the OP had a 2001 that they were working on the A/C system. They C/P some instructions about replacing the oil found in components. For the accumulator it stated to drill two 1/2" holes in the cylinder, drain and measure. I always assumed that turning it upside down was enough to get the oil out and never read or at least never ran across anything different here. What's correct? Wondering as I never found anything except a light film in the compressor on the system I'm working on right now.

HECAT on Thu August 08, 2013 9:44 AM

There are going to be many different opinions to drain, drill, measure, add this no matter what you measure, etc. The reason for the variety of ways it is is done and all the conflicting info, is that it is all a WAG. "Oil balancing" is the OE prescribed way to replace a component on a virgin system to get it thru warranty. On older systems that have been serviced, repaired, parts changed, and who knows what added to the system; then I personally think it becomes a joke to think it is a reliable practice.

Many times a system will leak or be low on charge when you see it for service. When removing components you find they lack much or any oil to be drained. This is because the oil loop did not have enough refrigerant to keep it flowing and most of it has pooled in the evap. But because no oil is draining from the components more oil is added to the system. Now it is overloaded with oil.

It is common practice and many experienced techs can and will do it regularly, but remember it is nothing more than a WAG.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

NickD on Thu August 08, 2013 12:30 PM

How about reading in another board from another idiot, me, you pitch the accumulator, remove and drain the compressor and flush it out with PAG, drain that, flush out the rest of the system, put it all back together again, then add the correct amount of PAG.

wptski on Thu August 08, 2013 5:39 PM

Quote
Originally posted by: NickD
How about reading in another board from another idiot, me, you pitch the accumulator, remove and drain the compressor and flush it out with PAG, drain that, flush out the rest of the system, put it all back together again, then add the correct amount of PAG.
Just trying to find my missing 8oz of oil.

HECAT on Fri August 09, 2013 8:37 AM

Quote
Originally posted by: wptski

Just trying to find my missing 8oz of oil.

Probaly pooled in the evap.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

u118224 on Fri August 09, 2013 2:10 PM

Quote
Originally posted by: NickD
How about reading in another board from another idiot, me, you pitch the accumulator, remove and drain the compressor and flush it out with PAG, drain that, flush out the rest of the system, put it all back together again, then add the correct amount of PAG.

Just curious, how does an AC Tech flush all the oil out of a auto AC system?

NickD on Fri August 09, 2013 3:32 PM

Lots variables here, typically a couple more or less ounces in each of the components, accumulator/receiver, compressor, depending on whether its mounted low or high, condenser, evaporator, in the lines or in the screen in the orifice or TXV. In like a good fashion York, all should be in the compressor sump, simple check when it has a sight glass. Due to capillary action, will never get all of it out.

If your lost of oil ended up in a compressor failure can be a slow drip someplace, may have to check along the highway.

Will leave how to flush out the system to Hecat. But also old fashion ways. With a failed compressor, not easy to flush out a parallel flow condenser. One thing for sure, system has to be surgically clean or that new compressor will fail again.

wptski on Fri August 09, 2013 7:10 PM

Not in the evaporator as 130psi couldn't push anything out. Considering how dirty the compressor was and the splattered up edge of the radiator, it came out fast from the shaft seal.

NickD on Sat August 10, 2013 7:23 AM

This all dates back to the older R-12 systems using mineral oil that is fairly immune to moisture absorption. The shear velocity of the refrigerant evenly distributes the oil through the entire system, when the compressor stops, depending on the geometry so much oil settles in each key component. Assuming none of the oil leaked out and say just the condenser fails without anything thing else failing and you just replace that, you add so much when changing that component.

Really a dumb idea somebody thought up with a hole in it, some of not all of the oil is going to be lost. And therefore all the other components would be low on oil, and its a guessing game as to how much oil was lost.

Only way to do it right is to flush out all the old oil, make the repairs, and add the recommended amount. No such thing as a dipstick in these systems. With PAG, even worse, a sludge and acids are formed and a lot more difficult to get it clean.

Just wasting your time in trying to figure out how much oil is left.

HECAT on Sat August 10, 2013 8:38 AM

Your not going to push oil out of an evap with a compressed gas. However, depending on the flow rate you may be able to push a little oil mist; thus creating the misconception that is all that is in there. The evap has a lower area for the liquid refrigerant to boil, this action causes oil to migrate out to feed the compressor; but all bets are off if there is not the proper amount of oil and the proper charge. There could be many ounces of oil in the bottom of an evap that the "blow" will just blow over.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

HECAT on Sat August 10, 2013 8:40 AM

Quote
Originally posted by: u118224
Quote



Just curious, how does an AC Tech flush all the oil out of a auto AC system?

To get a better understanding, start by reading the document in my signature.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

wptski on Sat August 10, 2013 8:48 AM

Quote
Originally posted by: HECAT
Your not going to push oil out of an evap with a compressed gas. However, depending on the flow rate you may be able to push a little oil mist; thus creating the misconception that is all that is in there. The evap has a lower area for the liquid refrigerant to boil, this action causes oil to migrate out to feed the compressor; but all bets are off if there is not the proper amount of oil and the proper charge. There could be many ounces of oil in the bottom of an evap that the "blow" will just blow over.
Well, if that's the case on my system, I'll find out after it's charger and it'll be my mistake to own up to.

NickD on Sat August 10, 2013 10:20 AM

Better off to list your problems and receive guidance as to how to repair it. Most of this is in the FAQ section of this board, had Chick use to say, do it right, do it once.

wptski on Sat August 10, 2013 1:02 PM

Quote
Originally posted by: NickD
Better off to list your problems and receive guidance as to how to repair it. Most of this is in the FAQ section of this board, had Chick use to say, do it right, do it once.
If I was charging somebody to do the job, I could say that I have to remove your whole front end "just" to disconnect the fittings on the condenser but I'm not. It seems every particular vehicle is a different animal and doing it right the first time could take a real long time. Us DIY'rs can listen and do up to a certain point what you guys suggest but when it turns into a real big project instead of a fairly simple one, we tend to skip over some of the suggestions. That may come back to haunt us but we try it anyway.

You should see some of the R-12>R134A conversion procedures outlined in some forums and they claim that it works without any issues at all.

I liked to talk to somebody that's disconnected the high side fitting on the evaporator on a '90 Buick Century with a 3.3L engine. Maybe if you cut the line off and use a socket on the fitting but now you need a new line which I've never seen for sale.

NickD on Sun August 11, 2013 7:40 AM

This is not your car, trying to help somebody on a different board? After working on two Fords with spring lock couplers, decided two is more than enough for one lifetime. You are trading your life to work on these. Surely don't see any advantage of drilling holes in an accumulator, what are you going to do with it, put corks in those holes?

EPA relinquished all the control over the OE's in manufacturing, but did place a $25,000.00 fine on techs if they don't recover, recover what because of the crap they are making today. Air? Also approving all these crazy blends only on the supposition they don't poke a hole in the ozone layer, nothing to do with long term performance.

Feel it time we have a second revolution.

wptski on Sun August 11, 2013 9:00 AM

Quote
Originally posted by: NickD
This is not your car, trying to help somebody on a different board? After working on two Fords with spring lock couplers, decided two is more than enough for one lifetime. You are trading your life to work on these. Surely don't see any advantage of drilling holes in an accumulator, what are you going to do with it, put corks in those holes?

EPA relinquished all the control over the OE's in manufacturing, but did place a $25,000.00 fine on techs if they don't recover, recover what because of the crap they are making today. Air? Also approving all these crazy blends only on the supposition they don't poke a hole in the ozone layer, nothing to do with long term performance.

Feel it time we have a second revolution.
Nope, it is my car! Just saying if one does this for a living, you don't care how much it takes to get to something because you just charge the customer. I didn't have a compressor failure but fittings are impossible to remove without major disassembly. The condenser might as well be replaced after what one has to go through just to loosen the lines. The evaporator high side line is low behind the traverse mounted engine. No problem if the engine was removed or just transmission linkage, master cylinder and exhaust manifold.

Drilled holes in my OEM accumulator looking for my missing oil but I have a new one, now installed. Now HECAT states that even blowing out the evaporator may not push any oil out. This is my only concern now or too much oil.

NickD on Mon August 12, 2013 8:11 AM

Is this a V-6 or a four? At my age, recently gave up on buying any FWD vehicle with a V-6 or a V-8, body can't take that beating anymore. FWD vehicles were intended only for four cylinder vehicles.

If they mentions all of the marriage liability laws, you would be a 1,000 times more careful in whom you would marry, really can get slathered with the wrong person. In like manner if they listed all the repair cost associated in buying a vehicle, everyone of us would walk out the door.

They do try to sell you a five year extended warranty plan for around $3,000.00, but if you read the fine print, no difference between the powertrain warranty. No longer happy in screwing you once, twice is what they try to do today.

Consumer Reports never reports stuff like this, more interested in complaining about tire that needs a couple of pounds of air. Other magazines are more interested in 0-60 times.

Definitely need a can of PB blaster and a prayer, and a 1,500 watt electric narrow flow heat gun and a set of crowfoot in both metric and English sizes plus a set of crowfoot flare s for those tight spaces. But if your service ports are leaking, have to replace those lines anyway. Or just cut the whole darn thing out and replace with all new. Again we go with throwaway. Not only in the AC system but everywhere else in the modern vehicles. How about a thousand bucks for an ABS modulator or 450 bucks for a POS fuel pump. Can't even give you an access plate for that, have to drain and drop the tank.

If we all left these pieces of crap on the showroom floor, this wouldn't be a problem. How about paying 160 bucks for four tire valves, use to be less than four bucks. We have both people in congress and in corporations that enjoy screwing the hell out of us. Just learned to enjoy being screwed.

HECAT on Mon August 12, 2013 8:48 AM

Quote
Originally posted by: wptski
Quote
Originally posted by: HECAT
Your not going to push oil out of an evap with a compressed gas. However, depending on the flow rate you may be able to push a little oil mist; thus creating the misconception that is all that is in there. The evap has a lower area for the liquid refrigerant to boil, this action causes oil to migrate out to feed the compressor; but all bets are off if there is not the proper amount of oil and the proper charge. There could be many ounces of oil in the bottom of an evap that the "blow" will just blow over.

Well, if that's the case on my system, I'll find out after it's charger and it'll be my mistake to own up to.

Probably won't know after it is charged up, unless is it so oil logged that the heat exchangers just won't perform as desired. Then we start chasing the symptoms (not the root cause) by adding extra fans and other methods to try and make it perform better. I hope this is not the case, and it all works out for you.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

wptski on Mon August 12, 2013 9:13 AM

It's a '90 Buick Century, 3.3L V6 with only 20K on it. It doesn't even have a EGR valve as it was so clean, didn't need one, I guess. MPG is so good that it didn't even qualify for the Cash for Clunkers program.

The Buick belonged to my parents but I've always driven RWD cars and last four were pickup trucks, all 4x4's but my latest is my first FWD/4WD SUV.

Using a crow foot seems out of the question, still because of limited room plus you have to hold both sides of the fitting or you'll twist the fixed side off! I've given up on the fittings. The compressor with a new shaft seal/gaskets, new accumulator is installed and piped together. Been playing with a new vacuum pump, etc. on it while deciding on trying R-134A or staying with R-12. Installed the R-134A fittings yesterday.

NickD on Mon August 12, 2013 2:19 PM

Here us your EGR Valve:



First an R-134a Ford Escape, now a prime 90 Buick, having problems keeping this straight.

With definitely stick with R-12 on this Buick, and this is also a brand new ballgame.

Do you want to find a Buick that didn't come with an EGR valve? Look at a 1971 or earlier.

wptski on Mon August 12, 2013 2:42 PM

Autozone/O'Reilly's, one shows a EGR valve for it and the other doesn't! Way back I found a write up on the 3300(LG7) engine which stated as I found, no EGR valve.

Nope, going to try R-134A first but I can always come back to R-12 as that was always the plan.