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flushing a compressor

2K views 15 replies 5 participants last post by  gordo999 
#1 ·
I know you're not supposed to flush AC system flushing agents through the compressor but is there a solvent/degreaser that could be flushed through a compressor?

I guess I am asking someone who may have taken a compressor apart what is inside. I saw a youtube video in which someone dismantled a compressor right down to the pistons and there seemed to be no rubber or plastic parts in there that could be affected by flushing with a mild solvent.

When I took the inlet/outlet tubes off the compressor there seemed to be a bit of black gunk on the inlet (low pressure) side. Nice green oil came out of the same hose. I want to run a mild solvent through it to see if any more gunk comes out, or fine metal bits.
 
#2 ·
If you are going to go through that much trouble, you might as well just disassemble the compressor and put in new seals. that way you can see if you have damaged internals or not. Getting the clutch off is the hardest part of the job, but the tool can be rented. Doing it this way means you get to clean it out completely, not worry about it failing due to bad seals that get damaged from the flushing agent and inspect it for wear. No point in putting a bad compressor back in and wasting all that time vacuuming it down and charging it.
 
#3 ·
redfury said:
If you are going to go through that much trouble, you might as well just disassemble the compressor and put in new seals.
Appreciate the input, RF. That was my next thought, to take it apart. I have some pullers and the job does not seem that bad.

The compressor is fairly new, however, and I was trying to avoid that. I have the system apart because the compressor was a bit noisy new and it seems to have gotten a bit more noisy. Some compressors can make a racket but my old one was not this noisy. Also, compressors tend to have a smooth noise whereas this one sounds a tad metallic. I can't decide whether it's a good compressor noise or a bad one.

When I pulled the system apart the orifice tube was blocked although the evaporator and condenser were clean.

I used a leak seal compound in the system and that may have gunked up the orifice tube although it's only supposed to seal holes when it contacts air. Since the AC system was cooling well when properly charged, even with the clogged orifice, I am optimistic that the compressor can't be that badly damaged. As you say, I'll never know till I pull it apart.
 
#4 ·
I have resealed several of these compressors and like you don't see where flush could hurt it but I don't think all the debris would come out without disassembling it.They come apart pretty easy and it only runs about $20 for the o rings and seal. The most common failure of a new compressor is from debris that was in the system on the vehicle that was not properly flushed out. New replacement compressors come with a suction side screen to prevent debris from damaging the compressor. some cheaper rebuilds don't come with the screen but you can buy it. My van had a replacement compressor on it when i bought it and its very noisy due to not having the screen to prevent debris from getting to the compressor . Its noisy but it works so I am going to run it until it blows
 
#6 ·
Just about any ac flush is just R11 refrigerant. you can buy a one time use can of flush with hose at autozone for $16. Or you can go big and buy a rx11 kit with reusable hose and gun for about $125. but the 2lb can refill for it runs me $80. I can flush 2 central air unit line sets and coil with 1 2lb can. So 1 can prob do at least 20 car ac systems. It only took 1/4 a can for my van to flush it front and rear, every coil and every line.
 

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#7 ·
:2:

Since you have evidence of compressor failure, I would strongly recommend not bothering with trying to use the old compressor. Just get a new or rebuilt unit, fill it with the proper oil and be done with it.

You've gone through all the trouble of disassembly and flushing the system. Why put the old, suspect compressor back in?
 
#9 ·
paulo57509 said:
Since you have evidence of compressor failure, I would strongly recommend not bothering with trying to use the old compressor.
That's the problem, I don't have evidence of compressor failure. All I have is a noisy compressor that's been noisy since I got it.

It has been blowing nice and cold since new, and lately, even with a blocked orifice tube.

It had oil in it when new and I added more, but I have no idea what type of oil was in it. I am going to drain it and use PAG 150, which is recommended for that type of compressor. If that quietens it I'll leave it alone but I want to ensure I have done everything I can to clean it out while it's out of the vehicle. I'm not really set up to pull it apart.
 
#10 ·
timothy47130 said:
Just about any ac flush is just R11 refrigerant.
I live in Canada and you can't use any refrigerant like R11 without a license. That's part of my problem. I have switched to Red Tek R12a, a mixture of propane and butane that has been doctored to make it safer and more effective as a refrigerant.

A lot of people knock R12a but I have no choice unless I want to become dependent on AC techs. Having read on it at length, R12a has several advantages over 134a. For one, it doesn't combine with water and corrode the system. For another, you only need about 1/3 the amount of R12a as 134a.

If I could fill up with 134a at a licensed dealer and have no issues for 5 years I'd likely do that. However, if I spring a leak, I am at the mercy of AC shops. Leaks are more likely on an aging system.
 
#11 ·
timothy47130 said:
They come apart pretty easy and it only runs about $20 for the o rings and seal. ....Its noisy but it works so I am going to run it until it blows
Thanks for input Timothy. It may be easy to get parts in the States but not here in Canada. I am hoping Trump wins and follows through on scrapping the trade deals. Maybe then we'll be able to buy the same parts as people in the States can buy.

I kind of share your attitude about letting it run till it blows. I am worried about what that means, however. If it jams in the middle of nowhere it could snap the serpentine belt unless the clutch lets go instantly. It it's a catastrophic failure, and the compressor shaft bends, there's no way to run the serpentine belt without one of those doohickeys for running the engine without the compressor. I've been thinking of buying one and keeping it in my van with a spare belt.
 
#12 ·
CopperFiremist said:
Give this stuff a shot.
Same problem I have mentioned before, I live in Canada and the supplier is in Florida. Some of them won't even ship to Canada and I have grown tired of asking.

Do you know Amazon won't ship tools and auto parts to Canada? They claim it's not them, that the problem lies between our governments.

Sears US won't ship parts and tools to Canada because they claim it interferes with Sears Canada. Are we talking free enterprise here or some kind of protectionist racket similar to what one might find in Third World countries?
 
#13 ·
wow ! I had no idea it was that hard to obtain certain auto parts and supplies in canada
 
#14 ·
timothy47130 said:
wow ! I had no idea it was that hard to obtain certain auto parts and supplies in canada
I don't want to create the impression it's that bad. Most parts for most vehicles are available through dealers and certain parts retailers. Also, most tools are available. We have retailers like Princess Auto and KMS Tools who specialize in inexpensive auto parts and tools.

The parts and tools that are hard to come by are specialty tools and parts like 0 - 50 inch-pound torque wrenches required for adjusting the bearing load on differentials. There are many specialty tools like that available in the States that are not freely available in Canadian stores.

I actually found a 0 - 50 inch pound bar-type torque wrench at KMS but it was not well advertised. I had to dig for it and twist a few arms. It was also a lot more expensive than what I could buy it for in the States but I was so happy to find one I did not care. As far as I know, after considerable research, KMS is the only tool outlet that carries that kind of torque wrench in Canada.

Same thing with specialty products like AC flush kits. That has more to do with government regulations that restrict the use of refrigerants like 134a to licensed techs.

I found a good 0 - 50 inch pound torque wrench on Amazon and they would not ship it to Canada. I have found that to be the case in several instances.
 
#15 ·
gordo999 said:
paulo57509 said:
Since you have evidence of compressor failure, I would strongly recommend not bothering with trying to use the old compressor.
That's the problem, I don't have evidence of compressor failure. All I have is a noisy compressor that's been noisy since I got it.

It has been blowing nice and cold since new, and lately, even with a blocked orifice tube.

It had oil in it when new and I added more, but I have no idea what type of oil was in it. I am going to drain it and use PAG 150, which is recommended for that type of compressor. If that quietens it I'll leave it alone but I want to ensure I have done everything I can to clean it out while it's out of the vehicle. I'm not really set up to pull it apart.
I might be mistaken, but I think you posted in another thread that there was oily, black goo (or something to that effect) that was in the system when you opened it up. The black stuff is the early signs of compressor failure.

Edit: Grammar.
 
#16 ·
paulo57509 said:
I might be mistaken, but I think you posted in another thread that there was oily, black goo (or something to that effect) that was in the system when you opened it up. The black stuff is the early signs of compressor failure.

Edit: Grammar.
No...you were not mistaken but I may have exaggerated the extent of the goo or gunk. The orifice tube was plugged with something black on the long end that fits into the evaporator inlet tube but the smaller screen on the high pressure end was completely clean. For some reason, it was still blowing cold air, suggesting enough refrigerant was getting past the orifice tube.

The black gunk on the orifice tube may have come from a sealant I introduced into the system that is meant to plug mechanical leaks in the system when it contacts air.

Neither the evaporator nor the condenser showed any signs of gunk, or shrapnel. I have found no metal shavings anywhere in the system or anything indicating a catastrophic failure.

Nice green oil was collecting in the high pressure tube just before the orifice tube and there was green oil in the hoses connecting the accumulator and condenser to the compressor.

There was a smear of sooty-like gunk right at the inlet to the suction side and I'm thinking I may have had a slight leak, due to the seal problem, that was allowing sooty air from the engine compartment to infiltrate. The leak could not have been bad, however, since it held a charge for months.

I am not claiming the compressor has not been stressed to some degree but I have no conclusive evidence that it is damaged to the point of imminent failure. It's easy to turn it by hand with the hoses disconnected and there are no mechanical noises to be heard.

Once I get it together with PAG 150 oil and a new orifice tube, I'll know a little more. I'm looking for it to operate more quietly and if it doesn't, I may have to pull it apart or exchange it.
 
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