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Post by turbokinetic on Oct 2, 2019 9:09:00 GMT
Excellent repair series. I have the same problem with a CK Monitor Top. I volunteered to help a local historical society fix their CK-2-B16, serial # 5283340. It has a 2-knob controller. The compressor stopped running 7 years ago. Upon discovering this forum, I downloaded the repair manual and started troubleshooting. Results: The compressor runs when the controller is bypassed. The controller contacts are OK, but the temperature bellows apply insufficient force to trip the contact arm. The sensing tube attached to the bellows does hot have an obvious hole like yours did, but the copper tubing is heavily corroded where it passes through the roof of the refrigerator. It may have a very slow leak. 2 questions: (1) To what pressure did you charge the new tube with refrigerant? (2) Would you consider taking in outside repair work like this for a fee? Good morning! Glad you were able to determine the compressor is still serviceable! That's always a good finding.
The tube is charged with saturated vapor at room temperature. In other words, the refrigerant can and tube are at the same temperature, in a 70 - 80 degree environment. Vapor only is charged into the tube, then it's sealed. I used R152A for this tube, as the working gas.
David
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Post by jjscalifornia on Oct 4, 2019 7:09:35 GMT
David, Thanks for the additional info. I understand from your YouTube profile that restoring refrigerators is not your main job, but would you be interested in taking on a side job to repair our bellows tube? John
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Post by turbokinetic on Oct 4, 2019 8:50:46 GMT
David, Thanks for the additional info. I understand from your YouTube profile that restoring refrigerators is not your main job, but would you be interested in taking on a side job to repair our bellows tube? John Hi John, I had send you a private message.
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Post by jjscalifornia on Oct 5, 2019 3:57:04 GMT
I have some more testing to complete on the historical society's CK-2-B16 Monitor Top refrigerator. I hope that only the temperature bellows is bad, but need to verify that the other components are OK to establish the repair scope.
Yesterday afternoon, the compressor was run for 1 hour with the controller bypassed. Unfortunately, the evaporator stayed warm, and the condenser did not heat up. I tried tapping on the top of the float enclosure, in case it was stuck. Is it possible that it could start cooling if run for a longer time, or is it more likely that the SO2 refrigerant charge is low?
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Post by turbokinetic on Oct 5, 2019 8:37:06 GMT
I have some more testing to complete on the historical society's CK-2-B16 Monitor Top refrigerator. I hope that only the temperature bellows is bad, but need to verify that the other components are OK to establish the repair scope. Yesterday afternoon, the compressor was run for 1 hour with the controller bypassed. Unfortunately, the evaporator stayed warm, and the condenser did not heat up. I tried tapping on the top of the float enclosure, in case it was stuck. Is it possible that it could start cooling if run for a longer time, or is it more likely that the SO2 refrigerant charge is low? Hi; sorry to hear you're having cooling problems!
It is tough to say what the problem could be; without seeing the machine first-hand. From what you've explained, there are a few bits of information which point to a leak, and others which point to a stuck float.
The fact that the machine sat for 8 years, will very often cause a stuck float. Also if there is even a tiny SO2 leak, it's pretty easy to smell it (which you haven't mentioned); and also there's almost always oil leakage to go along with the leak; which leaves an oily point. These points above seem to indicate there's not a leak.
The fact that the bellows tube was corroded; would possibly indicate a leak because SO2 is very corrosive when mixed with air and moisture.
Another thing which often happens is, someone foolishly defrosts the machine with a sharp instrument. They often cut the bellows tube, and puncture the evaporator at the same time. This causes a large leak, which loses all the SO2 at once. I would inspect the evaporator closely for any nicks and gouges.
For the stuck float, these often have to run for 10 - 15 minutes before they will start cooling after a long lay-up period. If it doesn't start cooling by its self, you can apply a heating gun to the float needle area (the part below the float, inside the fridge cabinet) where the smallest copper tube attaches. So this with the compressor running, after 15 minutes. This will ensure there is liquid in the float chamber. Heat it up, and then take a hard plastic tool, such as a screwdriver handle, and tap the float needle area side to side, going from one direction and then the other, back and forth, to see if flow is established,
Hopefully this will get it working!
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Post by jjscalifornia on Oct 5, 2019 9:57:56 GMT
Great info. I'll try heating and tapping the float valve needle and let you know how it turns out. It may not be for a couple of weeks, as the museum house, where the CK refrigerator is located, is open only on some weekends.
On a side note, how do you attach photos to these posts?
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Post by turbokinetic on Oct 5, 2019 11:06:55 GMT
Great info. I'll try heating and tapping the float valve needle and let you know how it turns out. It may not be for a couple of weeks, as the museum house, where the CK refrigerator is located, is open only on some weekends. On a side note, how do you attach photos to these posts? Hi John. It's great that you're working on one of these units in a historical home! That's always very cool.
As for the photos, our forum has had space limitations for a while now. There is no easy solution from an administrative standpoint. In the meantime, we have been hosting the pictures on external sites, and linking to them here. I have a private server which is part of my e-mail account with a local ISP. Others are using various third-party photo hosting sites; or they are sharing the photos on Google Drive.
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Post by jjscalifornia on Oct 21, 2019 21:49:24 GMT
Update on the CK Monitor Top in the historical home, located in the Muller House Museum, San Pedro, CA: No success yet: This past Saturday, I ran the refrigerator for a few hours with the controller bypassed. Periodically, the float valve tube inside the cabinet was heated to a quite warm temperature with a heat gun, and I tapped on it in all directions with a screwdriver handle. But, the evaporator did not cool at all. The condenser on top stayed cool, or may have heated up very slightly, probably due to the compressor running for a couple of hours. I also tried heating up the evaporator coils with the heat gun.
After running a couple of hours with the door closed, there was a slight sharp odor inside the cabinet. I cannot say that it was a refrigerant leak because I do not know what SO2 smells like. It was a sharp odor, something like ammonia. My concern is that the refrigerant has all leaked out and the smell is from residual gas that is boiling out of the compressor oil. Any ideas for checking the refrigerant pressure without specialized equipment, or with readily available equipment?
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Post by ckfan on Oct 23, 2019 15:32:05 GMT
Ah, I’m sorry to hear that. It does sound like something may be escaping. Do you see oil or corrosion anywhere? If the SO2 leaked out you would see lots of corrosion where it happened.
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Post by turbokinetic on Oct 23, 2019 17:11:13 GMT
Update on the CK Monitor Top in the historical home, located in the Muller House Museum, San Pedro, CA: No success yet: This past Saturday, I ran the refrigerator for a few hours with the controller bypassed. Periodically, the float valve tube inside the cabinet was heated to a quite warm temperature with a heat gun, and I tapped on it in all directions with a screwdriver handle. But, the evaporator did not cool at all. The condenser on top stayed cool, or may have heated up very slightly, probably due to the compressor running for a couple of hours. I also tried heating up the evaporator coils with the heat gun. After running a couple of hours with the door closed, there was a slight sharp odor inside the cabinet. I cannot say that it was a refrigerant leak because I do not know what SO2 smells like. It was a sharp odor, something like ammonia. My concern is that the refrigerant has all leaked out and the smell is from residual gas that is boiling out of the compressor oil. Any ideas for checking the refrigerant pressure without specialized equipment, or with readily available equipment? It's not easy to check without specialized equipment. You can crack the bleed screw and see if pressure escapes. The risk here is that the screw doesn't seal up properly afterwards. SO2 does tend to corrode things but it needs moisture to do that. If it leaks in a dry environment, there will probably not be much corrosion. In light concentrations, SO2 smells like burned match heads, or the smell around an active volcano. In high concentrations, it causes sneezing. wheezing, and eye watering. Most of these old cabinets have some sort of odor to them it seems. I installed a unit which was running a newer, odorless refrigerant onto an old cabinet. I could swear the interior smelled like SO2 but it couldn't be since none is in the machine. The good news is; the CK machines work with R152A just as good as they did with SO2; and there is no conversion or oil exchange needed. Just charge it and go. You'll need to locate the leak and repair it, then the charging will be relatively straightforward.
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Post by jjscalifornia on Oct 24, 2019 5:41:17 GMT
No, I did not see oil or corrosion, but there may be corrosion where tubing passes through the roof of the cabinet. The temperature sense tube was most severely corroded between the outside and inside surfaces of the top. If the SO2 refrigerant did leak, it could have been years ago.
I will try your suggestion to crack open the bleed screw. First, I will flood the area with oil, as suggested on p. 147 of the GE manual. That should indicate whether the screw seals afterwards, if there is any pressure inside to start with.
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Post by turbokinetic on Oct 24, 2019 13:21:21 GMT
No, I did not see oil or corrosion, but there may be corrosion where tubing passes through the roof of the cabinet. The temperature sense tube was most severely corroded between the outside and inside surfaces of the top. If the SO2 refrigerant did leak, it could have been years ago. I will try your suggestion to crack open the bleed screw. First, I will flood the area with oil, as suggested on p. 147 of the GE manual. That should indicate whether the screw seals afterwards, if there is any pressure inside to start with. Sounds like a very good plan. Hope to hear a positive outcome! Very often, people try to tip the fridge over to transport it; resulting in the top falling off, or partially falling off. They often end up breaking one or more of the lines near the evaporator. If this happened many years ago and the unit has been in a relatively dry environment, you could have only small amounts of odor remaining, and little corrosion. The fact that there's any corrosion is of concern.
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Post by jjscalifornia on Nov 1, 2019 5:33:41 GMT
It's hard to say what happened. I am told that it used to work, and then stopped 7 years ago.
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Post by turbokinetic on Nov 1, 2019 13:54:08 GMT
It's hard to say what happened. I am told that it used to work, and then stopped 7 years ago. It It is hard to say! One of the things that I have learned is "let the machine tell its story" and don't depend on people for the whole story or the correct story. For instance, nobody ever abuses or lets the top fall off one of these.... until you show them the broken line and the scratched cabinet where it impacted the edge. I'm not saying that is what happened - just saying don't let their story that "it just stopped working" cloudy up your methodical troubleshooting. Sincerely, David
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Post by jjscalifornia on Nov 25, 2019 6:51:39 GMT
I'll keep that in mind. For the past few weeks, I have been neglecting the refrigerator in order to take care of some outdoor jobs around the house while the weather is still good. Hope to get back to the CK next week.
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