A/C on the truck in my sig has had a slow leak for a couple of years and I topped it off at the beginning of the summer and it'd been running fine. Other day when it was 98 degrees outside I decided it wasn't doing 'quite good enough' and put another couple ounces of Freon in it (I only have a low pressure side gauge). Anyhow I left it running and went inside for a few minuets and when I came back out my compressor had locked up and was smoking the clutch. Next day I tried and I could spin the compressor by hand, but the clutch won't engage anymore. Any chance I just added a little to much Freon and could get away with just replacing the clutch for now? Compressor is about 3 years old.
A/C compressor question
- Thread starter nwjones18
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OK, looks like the compressor stalled when near-liquid refrigerant made it into the low side port of the compressor or the stall occurred when the hi side line jammed solid with refrigerant up to the expansion valve.
Try the easy bit: find the fuse for the clutch and see if it's good. Swap in a spare, some fuses can open and you won't see it 1% of the time, the rest blow with a nice big black scorch mark so they're easy to spot.
If you can access the connector to the clutch test the Ohms value of the clutch winding, should be well under 12 Ohms, if open, it needs replacing.
If you can't access the connector at the clutch, remove the fuse, turn on the ignition key, in Volts mode find which side of the fuse is 12V, go to the other side and then switch to Ohms and measure the resistance to ground, while having the A/C switch on. On late model cars and trucks, it's possible a electric module is fed by the fuse before the clutch and readings will be misleading or inconclusive, on older cars/trucks the fuses goes straight to the clutch via mechanical switches and wiring and no electronics.
The idea is really test to see the clutch winding is not fried. If the clutch engages and slips, you still need service, but you'll know you should 80% when done.
Test your low side pressure with the system at rest, refrigerant should still be there. Don't be surprised if in the shade it reads lower then in the hot sun for 3 hours, that's normal.
Try the easy bit: find the fuse for the clutch and see if it's good. Swap in a spare, some fuses can open and you won't see it 1% of the time, the rest blow with a nice big black scorch mark so they're easy to spot.
If you can access the connector to the clutch test the Ohms value of the clutch winding, should be well under 12 Ohms, if open, it needs replacing.
If you can't access the connector at the clutch, remove the fuse, turn on the ignition key, in Volts mode find which side of the fuse is 12V, go to the other side and then switch to Ohms and measure the resistance to ground, while having the A/C switch on. On late model cars and trucks, it's possible a electric module is fed by the fuse before the clutch and readings will be misleading or inconclusive, on older cars/trucks the fuses goes straight to the clutch via mechanical switches and wiring and no electronics.
The idea is really test to see the clutch winding is not fried. If the clutch engages and slips, you still need service, but you'll know you should 80% when done.
Test your low side pressure with the system at rest, refrigerant should still be there. Don't be surprised if in the shade it reads lower then in the hot sun for 3 hours, that's normal.
Nope. Once it locks up its a goner. Plus its probly the front seal on the compressor thats been leaking anyway. Dont forget the tube and accumulator too.
Time for a shop with proper tools & equipment.
You can jump 12 directly to the clutch and see if it engages, otherwise you need a compressor. I agree, he either over charged it , or slugged it by holding the can the wrong way when filling.
Originally Posted By: Donald
Time for a shop with proper tools & equipment.
When I did my wife's compressor I bought the tools and equipment and still came out ahead. When I get around to fixing the leak in my own A/C, I'll be way ahead.
Time for a shop with proper tools & equipment.
When I did my wife's compressor I bought the tools and equipment and still came out ahead. When I get around to fixing the leak in my own A/C, I'll be way ahead.
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Originally Posted By: nwjones18
A/C on the truck in my sig has had a slow leak for a couple of years and I topped it off at the beginning of the summer and it'd been running fine. Other day when it was 98 degrees outside I decided it wasn't doing 'quite good enough' and put another couple ounces of Freon in it (I only have a low pressure side gauge). Anyhow I left it running and went inside for a few minuets and when I came back out my compressor had locked up and was smoking the clutch. Next day I tried and I could spin the compressor by hand, but the clutch won't engage anymore. Any chance I just added a little to much Freon and could get away with just replacing the clutch for now? Compressor is about 3 years old.
Could be a number of things. Was the charging can still connected when it seized up, or were you just running it post-charge? If the charging can was connected, there's a good chance it over-charged or "slugged" the compressor with liquid and toasted the clutch. The fact you can spin it now means the liquid is gone, but the compressor still could be damaged (broken valves, etc.) from trying to compress the incompressible- just like hydro-locking an engine.
The other possibility is common with leaking systems: every time it leaks down it loses both refrigerant and lubricating oil. When you keep charging it, the system gets lower and lower on oil until the compressor seizes up. Sometimes a compressor will seize hot and then loosen up as it cools down- but its never the same afterward.
On the other hand, if it was just sitting there cycling and running normally it COULD be that the clutch just happened to give out with the extra load of a normal charge, and the compressor itself is fine. Maybe you could get away with a new clutch.
Either way if it were mine, I'd R&R both if I could afford it just to be on the safe side. And find/fix the leak at the same time.
A/C on the truck in my sig has had a slow leak for a couple of years and I topped it off at the beginning of the summer and it'd been running fine. Other day when it was 98 degrees outside I decided it wasn't doing 'quite good enough' and put another couple ounces of Freon in it (I only have a low pressure side gauge). Anyhow I left it running and went inside for a few minuets and when I came back out my compressor had locked up and was smoking the clutch. Next day I tried and I could spin the compressor by hand, but the clutch won't engage anymore. Any chance I just added a little to much Freon and could get away with just replacing the clutch for now? Compressor is about 3 years old.
Could be a number of things. Was the charging can still connected when it seized up, or were you just running it post-charge? If the charging can was connected, there's a good chance it over-charged or "slugged" the compressor with liquid and toasted the clutch. The fact you can spin it now means the liquid is gone, but the compressor still could be damaged (broken valves, etc.) from trying to compress the incompressible- just like hydro-locking an engine.
The other possibility is common with leaking systems: every time it leaks down it loses both refrigerant and lubricating oil. When you keep charging it, the system gets lower and lower on oil until the compressor seizes up. Sometimes a compressor will seize hot and then loosen up as it cools down- but its never the same afterward.
On the other hand, if it was just sitting there cycling and running normally it COULD be that the clutch just happened to give out with the extra load of a normal charge, and the compressor itself is fine. Maybe you could get away with a new clutch.
Either way if it were mine, I'd R&R both if I could afford it just to be on the safe side. And find/fix the leak at the same time.
Originally Posted By: Donald
Time for a shop with proper tools & equipment.
Nice vote of confidence. You're basically calling the OP an idiot.
Time for a shop with proper tools & equipment.
Nice vote of confidence. You're basically calling the OP an idiot.
Originally Posted By: Merkava_4
Originally Posted By: Donald
Time for a shop with proper tools & equipment.
Nice vote of confidence. You're basically calling the OP an idiot.
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment.
He's right.
Originally Posted By: Donald
Time for a shop with proper tools & equipment.
Nice vote of confidence. You're basically calling the OP an idiot.
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment.
He's right.
Originally Posted By: rooflessVW
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
440Magnum called it.
A neighbor sent a truck over to us that no longer engaged its compressor clutch. It had a leaky high-side schraeder valve and they had been topping off refrigerant for months without adding any oil to it. He wanted the entire compressor replaced as opposed to just doing the clutch itself.
When the compressor was removed, my tech brought it over to me. He turned it straight upside down, and exactly nothing came out. This was pretty amazing, considering this particular truck is notorious for compressor chatter due to oil pooling down in its low mounted compressor. When I tried to turn it by hand, it turned very gritty, and I could see one dry piston scraping along through the suction port.
Amazingly, there was no metal contamination in the system. After suggesting a full AC service anyway, he decided to just replace the compressor and charge the system with correct oil and refrigerant. It's working for now. He is completely aware that it may not stay that way.
If you have a leak on a low-mounted compressor, complete evacuation of the oil is a given.
When the discharge line on my Ram was leaking, it left a massive amount of oil on the suspension in only a few hours of operation from a pinhole leak.
A neighbor sent a truck over to us that no longer engaged its compressor clutch. It had a leaky high-side schraeder valve and they had been topping off refrigerant for months without adding any oil to it. He wanted the entire compressor replaced as opposed to just doing the clutch itself.
When the compressor was removed, my tech brought it over to me. He turned it straight upside down, and exactly nothing came out. This was pretty amazing, considering this particular truck is notorious for compressor chatter due to oil pooling down in its low mounted compressor. When I tried to turn it by hand, it turned very gritty, and I could see one dry piston scraping along through the suction port.
Amazingly, there was no metal contamination in the system. After suggesting a full AC service anyway, he decided to just replace the compressor and charge the system with correct oil and refrigerant. It's working for now. He is completely aware that it may not stay that way.
If you have a leak on a low-mounted compressor, complete evacuation of the oil is a given.
When the discharge line on my Ram was leaking, it left a massive amount of oil on the suspension in only a few hours of operation from a pinhole leak.
It locked up after I had disconnected the can, and the compressor locked up but the belt was still turning the clutch. It was smoking by the time I found it. I suspect that oil leaked out as well, but there is no obvious oil anywhere that I can see. I have bought a proper set of gauges and a vacuum pump since and intend to do the job correctly when it cools down a little, but I just saw a new clutch for $50 and thought 'sure would nice to get that and limp through the rest of summer'. I'll see if the fuse is blown to the clutch as well, but I think it just cooked itself.
Originally Posted By: Merkava_4
Originally Posted By: rooflessVW
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
You mean you changed a component and had a shop deal with vacuuming and properly charging the system? That's a little different from the OP's "I didn't think it was good enough so I shot some more freon in it and locked up my compressor," isn't it?
How did you properly recycle the refrigerant in the system when you removed your compressor?
Originally Posted By: rooflessVW
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
You mean you changed a component and had a shop deal with vacuuming and properly charging the system? That's a little different from the OP's "I didn't think it was good enough so I shot some more freon in it and locked up my compressor," isn't it?
How did you properly recycle the refrigerant in the system when you removed your compressor?
I've never understood why a/c work is such a polarizing topic. If OP can fix his compressor, great. The tools (vacuum pump, manifold gauges, flush gun) aren't going to change much and he'll have them if he ever needs them again. I'm starting to think (well, no, I already thought) that its nothing more than the trade desperately trying to keep itself a secret.
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The trade is not trying to keep itself a secret. People keep it a secret from themselves, and companies that make "ez duz it" AC fixes throw even more kitty litter over the whole thing.
Most people look at the cost of purchasing the correct equipment and immediately decide to half-moon the process. Lacking the proper information and tools, they usually end up destroying the whole system.
Knowing this, companies make completely inadequate products to service AC systems, often leading to disaster. If your system needs a 26 oz. charge of refrigerant, you are in deep trouble that a simple recharge will not fix. Charging a system using only the low-side pressure, with absolutely no temperature/humidity reference is insane. Stop-leak refrigerant should be banned. Ever seen what an orifice tube looks like after that garbage goes through it?
Of all of the times I have told people that they needed a complete system service, more often than not, they want a half-measure performed.
Most people look at the cost of purchasing the correct equipment and immediately decide to half-moon the process. Lacking the proper information and tools, they usually end up destroying the whole system.
Knowing this, companies make completely inadequate products to service AC systems, often leading to disaster. If your system needs a 26 oz. charge of refrigerant, you are in deep trouble that a simple recharge will not fix. Charging a system using only the low-side pressure, with absolutely no temperature/humidity reference is insane. Stop-leak refrigerant should be banned. Ever seen what an orifice tube looks like after that garbage goes through it?
Of all of the times I have told people that they needed a complete system service, more often than not, they want a half-measure performed.
Originally Posted By: rooflessVW
Originally Posted By: Merkava_4
Originally Posted By: rooflessVW
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
You mean you changed a component and had a shop deal with vacuuming and properly charging the system? That's a little different from the OP's "I didn't think it was good enough so I shot some more freon in it and locked up my compressor," isn't it?
How did you properly recycle the refrigerant in the system when you removed your compressor?
Well, not saying he did this, but I took my car to the Shop and paid to have them Evac it properly.
Then I vac'd it and charged it myself.
Still have my vaccum pump and gauges, and 13lbs of R134 for the next time.
Originally Posted By: Merkava_4
Originally Posted By: rooflessVW
No, he's saying that AC isn't something that should be dicked around with without proper tools and equipment. He's right.
I don't have any A/C equipment and I managed to fix mine just fine. I replaced the compressor and then took the car to a shop for charging the system. It was a piece of cake; the compressor slides out the right front wheel well.
You mean you changed a component and had a shop deal with vacuuming and properly charging the system? That's a little different from the OP's "I didn't think it was good enough so I shot some more freon in it and locked up my compressor," isn't it?
How did you properly recycle the refrigerant in the system when you removed your compressor?
Well, not saying he did this, but I took my car to the Shop and paid to have them Evac it properly.
Then I vac'd it and charged it myself.
Still have my vaccum pump and gauges, and 13lbs of R134 for the next time.
Originally Posted By: DoubleWasp
The trade is not trying to keep itself a secret. People keep it a secret from themselves, and companies that make "ez duz it" AC fixes throw even more kitty litter over the whole thing.
Most people look at the cost of purchasing the correct equipment and immediately decide to half-moon the process. Lacking the proper information and tools, they usually end up destroying the whole system.
Knowing this, companies make completely inadequate products to service AC systems, often leading to disaster. If your system needs a 26 oz. charge of refrigerant, you are in deep trouble that a simple recharge will not fix. Charging a system using only the low-side pressure, with absolutely no temperature/humidity reference is insane. Stop-leak refrigerant should be banned. Ever seen what an orifice tube looks like after that garbage goes through it?
Of all of the times I have told people that they needed a complete system service, more often than not, they want a half-measure performed.
This x 1000. A/C is no big secret, it's not a conspiracy or a special club and it's not actually hard to do *right*. Like anything, you need a bit of know-how and tools, and it's a bit harder than it used to be to half-arse either the knowledge or the tools. Modern systems are fussy, precise and clean. (Did I mention clean?)
To service A/C you can do it two ways.
A) Read the bloody instructions and use the right tools. When it says Vacuum the system to 700 microns, get a [censored] micron gauge and do it right. Your harbour freight pneumatic vacuum pump won't ever get within a bulls roar of that, so get a cheap dual stage rotary oil sealed pump. When it says add 500g +/-25g of refrigerant, DO THAT. Exactly!. Figure out how much your hose & gauge set holds, put the bottle on a set of vaguely accurate scales and weigh it in properly. If you follow the instructions and use the right tools you don't actually have to learn anything, think, or do much more than grunt and twist knobs. Most knuckle draggers can get that far and not cock it up.
B) Learn how refrigeration systems work. They're not rocket science and simply rely on some very well known laws of thermodynamics. If you do that, then you can start using gauges and actually assessing system performance because you'll know what the numbers mean. Hint. Low side gauges that say "good/low" are useless under *all* conditions. Unfortunately to do this you have to read a bit, ask some questions and be willing to fight through the knuckle draggers responses "ugh, I just use 5 ov em blow off cans and it's rool cold" to get actual scientific answers and learn a bit about how the tools work and why the tools work. There are *loads* of good books out there in paper and pdf and forums are full of people with actual knowledge. (They're also full of blowhards who know enough to parrot something the read somewhere else, but a bit of critical thought soon has you seeing through that).
You can't just squirt a bit of gas in there and expect to get it right (although you can get extremely lucky and not hydrolock a compressor and get a passably working system). How do you know how much leaked out? Why did it leak out? Where did it leak out? Did you fix the leak? If you put gas in it now, how much will be in it tomorrow?
If you don't want to follow the instructions or actually invest in some tools and knowledge, then get a "pro" to do it. Thanks to the wonders of E-bay, the tools are affordable (although a recovery machine is getting a bit spendy. Still, do you want to do it right?).
The trade is not trying to keep itself a secret. People keep it a secret from themselves, and companies that make "ez duz it" AC fixes throw even more kitty litter over the whole thing.
Most people look at the cost of purchasing the correct equipment and immediately decide to half-moon the process. Lacking the proper information and tools, they usually end up destroying the whole system.
Knowing this, companies make completely inadequate products to service AC systems, often leading to disaster. If your system needs a 26 oz. charge of refrigerant, you are in deep trouble that a simple recharge will not fix. Charging a system using only the low-side pressure, with absolutely no temperature/humidity reference is insane. Stop-leak refrigerant should be banned. Ever seen what an orifice tube looks like after that garbage goes through it?
Of all of the times I have told people that they needed a complete system service, more often than not, they want a half-measure performed.
This x 1000. A/C is no big secret, it's not a conspiracy or a special club and it's not actually hard to do *right*. Like anything, you need a bit of know-how and tools, and it's a bit harder than it used to be to half-arse either the knowledge or the tools. Modern systems are fussy, precise and clean. (Did I mention clean?)
To service A/C you can do it two ways.
A) Read the bloody instructions and use the right tools. When it says Vacuum the system to 700 microns, get a [censored] micron gauge and do it right. Your harbour freight pneumatic vacuum pump won't ever get within a bulls roar of that, so get a cheap dual stage rotary oil sealed pump. When it says add 500g +/-25g of refrigerant, DO THAT. Exactly!. Figure out how much your hose & gauge set holds, put the bottle on a set of vaguely accurate scales and weigh it in properly. If you follow the instructions and use the right tools you don't actually have to learn anything, think, or do much more than grunt and twist knobs. Most knuckle draggers can get that far and not cock it up.
B) Learn how refrigeration systems work. They're not rocket science and simply rely on some very well known laws of thermodynamics. If you do that, then you can start using gauges and actually assessing system performance because you'll know what the numbers mean. Hint. Low side gauges that say "good/low" are useless under *all* conditions. Unfortunately to do this you have to read a bit, ask some questions and be willing to fight through the knuckle draggers responses "ugh, I just use 5 ov em blow off cans and it's rool cold" to get actual scientific answers and learn a bit about how the tools work and why the tools work. There are *loads* of good books out there in paper and pdf and forums are full of people with actual knowledge. (They're also full of blowhards who know enough to parrot something the read somewhere else, but a bit of critical thought soon has you seeing through that).
You can't just squirt a bit of gas in there and expect to get it right (although you can get extremely lucky and not hydrolock a compressor and get a passably working system). How do you know how much leaked out? Why did it leak out? Where did it leak out? Did you fix the leak? If you put gas in it now, how much will be in it tomorrow?
If you don't want to follow the instructions or actually invest in some tools and knowledge, then get a "pro" to do it. Thanks to the wonders of E-bay, the tools are affordable (although a recovery machine is getting a bit spendy. Still, do you want to do it right?).
Originally Posted By: SHOZ
It's common here for someone to be ostracized for wanting to do something themselves.
I don't get that. Isn't this a site full of car guys?" Don't most car guys work on their own vehicles? I know for me, the number of times a shop has screwed something up is higher than the number of times I've screwed something up.
It's common here for someone to be ostracized for wanting to do something themselves.
I don't get that. Isn't this a site full of car guys?" Don't most car guys work on their own vehicles? I know for me, the number of times a shop has screwed something up is higher than the number of times I've screwed something up.
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