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Post by coldspaces on Sept 26, 2015 1:16:22 GMT
This is my first time trying to open one of these floats. I don't have a lath but it sure is the way they should be open if possible. I ground off the weld and did not get it as accurate as I would have liked.  I did however get it open and found that it was much cleaner inside than I thought it would be. Pic of the flush shows all the small black crud that I flushed out of the float. White pieces are paint that fell off unit into the flush.   Even all the needle and seat area were very clean. Looks like the CF20 will break this black crud.oh and it also removes the paint too.   From what I can see so far the needle and seat are in good shape. Must get saved by the lubricating properties that so2 is supposed to have.   And here is my big mistake. I crushed the float ball using too much pressure. Had the guide pin been in it might have still worked but probably would have been binding on pin too much. As it is it deformed the ends enough to rip open next to the top pin guide and that is why it wouldn't float anymore. I will never be using that much pressure on the ball again. Backward through from the outlet side with float open to atmosphere only for high pressure from now on. Well now I am hoping that maybe Alan will have an extra float ball and save my *#+. If not will be opening up some more floats to try to find one. Alan can probably help me there and let me know if most of the DR float balls are made the same or not. I see no reason for these float to have been welded shut if the ball can't take much pressure. I plan to solder it with Stay Brite 8, it will handle the job as far as pressures are concerned. I also see no reason that the housing can't be a little shorted if need be other than having to shorten the pin also. There is a machined area for the bottom to fit in that will limit how much it can be lowered unless more clearance it machined in it. There is plenty of room above the float ball to lower the housing some if needed. At this time I need advice from other Monitor Top experts to guide my next steps.   |
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Post by allan on Sept 26, 2015 1:38:28 GMT
Great surgery job! Love all the good pics. I have opened a few floats and interestingly the float and chambers have been very clean overall. Just a small amount of black crud around the seat and needle. After studying your pics it appears this float is like the ones I have opened, having a small amount of crud inside.
Another common detail is the condition of the liquid strainer, which appears to be very badly plugged. All of mine have been this way. Please soak the strainer and see if the cfc20 cleans it.
I will look around and see if I can find you a float. I would strongly suggest to not use stay brite on this reassembly. It will give you trouble in the future
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Post by coldspaces on Sept 26, 2015 1:44:21 GMT
Great surgery job! Love all the good pics. I have opened a few floats and interestingly the float and chambers have been very clean overall. Just a small amount of black crud around the seat and needle. After studying your pics it appears this float is like the ones I have opened, having a small amount of crud inside. Another common detail is the condition of the liquid strainer, which appears to be very badly plugged. All of mine have been this way. Please soak the strainer and see if the cfc20 cleans it. I will look around and see if I can find you a float. I would strongly suggest to not use stay brite on this reassembly. It will give you trouble in the future I don't see why the Stay brite should be an issue but I sure could be wrong, can you elaborate? It has very high tensile strength (for solder anyway) and should flow out on steel with the correct flux. I would do it while right side up and draw it up into the joint to avoid excess running into the float. Also flush afterwards to clean out all flux. I do have a mig welder but am not confidant I can do a good enough job to make it leak free. I was planning to look at the strainer closer tonight I had no trouble running flush into the float through it but the pic does make it look pretty dirty. Will sure try the CF20 and see what it does to it. Thanks for the help and advice Alan. |
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Post by coldspaces on Sept 26, 2015 3:30:47 GMT
Ok here are some pics of the float inlet screen. Here is it with a flashlight shining through it. Remember that this screen has already had POE oil, CF20 and Pro Flush run through it in the last few days. It is pretty well open but not completely clean.  If you zoom in on this with Picasa viewer or such you can see that there is still stuff on the screen. You can't see it here because of the flash but the side opposite the screen has some crud built up on it still.  Added a little CF20 and let it soak for only 10 minutes. At least 15 minutes is recommended.You can see better here the layer of crud in the end of the housing opposite the screen.  Scrubbed the screen and crud near it lightly with a flux brush. Most of the of the crud came off fairly easy. Still have to keep in mind that it was first soaked for 2 days in POE oil but I think it didn't do much based on how clean it was when I drained it out. Although if it takes both to brake this crud I will next be mixing them together if that's what it takes.  Here's a little closer shot of the screen after cleaning.  And here it is again with the light shining through.  Much cleaner than it was but a longer soak will do even better I am sure.  |
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Post by allan on Sept 26, 2015 3:50:07 GMT
Great discovery! This tells me we can restore these floats without removal. With you sacrificing this float and teaching us about the innards and effective cleaning solutions I am positive we can drill 2 -3/8 inch holes in the sides at the very bottom 180 degrees apart and then drill a third one directly above the screen in the inlet copper tube. After all cleaning is complete do a final flush and nitro purge to remove all debris. Anything remaining is going directly to the suction inlet screen and that is no good so this will eliminate this problem. Then seal up the 3/8 holes in the tank with copper plug and stay silv 45% silver. A neat solder over can be performed on the copper inlet tube! Thanks explorer cold Spaces! I will find you some parts
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Post by coldspaces on Sept 26, 2015 4:30:01 GMT
Sacrificed? I am planing to make it work again with the replacement float. Need at least the same base so it has the correct orifice size don't I?
I suppose the 45% is a better choice than Stay Brite to seal it all shut. Was hoping not to get it that hot though. What do you think?
I was hoping that it would clean it without drilling it full of holes. Not sure how effective it is though having only done one float with the Cf20 so far. might be just as well to cut them wide open so that you know everything is clean.
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Post by allan on Sept 26, 2015 12:47:55 GMT
That float looks exactly like my DR1 float that I cut the hole in the side of. With the DR1 being the smallest refrigerant flow it's going to be interesting to compare the orfice size with yours, which has to have much higher flow rate with those 2 large evaps. Can you get an accurate measurement of the orfice? What will be the most accurate way to measure, a gas orfice drill set? I would not be surprised if the orfice sizes are the same
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Post by allan on Sept 26, 2015 21:47:23 GMT
Here is a replacement float and rod. Hope it is the correct size. Tip to tip is 3-5/8 inches, diameter just below the seam measures 2-7/16 inches. Spring was gone? Which seems very strange. I wonder if it just dissolved?  |
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Post by vintageguy on Sept 27, 2015 3:48:39 GMT
Here is a replacement float and rod. Hope it is the correct size. Tip to tip is 3-5/8 inches, diameter just below the seam measures 2-7/16 inches. Spring was gone? Which seems very strange. I wonder if it just dissolved? You got that at Starbucks? |
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Post by coldspaces on Sept 27, 2015 14:47:16 GMT
Here is a replacement float and rod. Hope it is the correct size. Tip to tip is 3-5/8 inches, diameter just below the seam measures 2-7/16 inches. Spring was gone? Which seems very strange. I wonder if it just dissolved? That looks like a match. I can't get an accurate measure on the length with the ends crushed in but I think it's the same. There was no spring in this one either. Did they only put them in the early floats that could be manually lifted? Also mine does not have the washer I see on the top end of the guide pin,what does it do? As for orifice size there is only the hole in the float seat. No real length to it like the float drawings seem to show. .023 mig welding wire fits in it with maybe a few thousands to spare. 0.28 cap tube checker will not fit. At this point I have nothing handy in between those two sizes to try. The tube from the float to the evaps looks to be thicker wall than normal and is approximately .125" inside diameter. |
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Post by coldspaces on Sept 28, 2015 2:16:23 GMT
Rechecking the DR manual I guess the DR floats didn't have an orifice other than the hole in the float seat. At least it is not shown in the cutaway drawing.  |
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Post by coldspaces on Sept 28, 2015 4:24:13 GMT
Ok so I was looking at this float and thought the outlet tube was soft soldered into the float. Figured it would be easy to remove so I tried. When I unsoldered it lots of solder fell out but I soon found out it is just a brass sleeve that is place over the outlet tube. Not sure just why it was done this way.  The outlet tube is 45% brazed in based on the color of the braze. I wrapped the float seat with wet towels and tried to un-braze the outlet tube. Probably shouldn't have tried but I did. Ended up it wasn't coming out and I am having to drill it out to replace it. If it turns out the ID of the outlet tube is critical I may be adding a restrictor in the new outlet tube. I really think that the float will control it and it won't matter if the replacement tube is larger inside.  Got the sides of the base sanded up pretty nice.  As you can see here the sleeve did not fill with solder all the way. If it was intended to seal it from corrosion it didn't get it all. Interesting that the tube is steel and the float arm support is brass. Looks like the steel tube must be one piece with the base and the float seat brazed or fused someway to it. That explains why i didn't seem to see any braze or solder were the steel tube meets the bottom side of the base. Sure am learning a lot, hope I can make it work again.  |
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Post by allan on Sept 29, 2015 2:09:52 GMT
Rechecking the DR manual I guess the DR floats didn't have an orifice other than the hole in the float seat. At least it is not shown in the cutaway drawing. I was aware that there was no orfice other than the hole under the needle. And notice how the outlet tube is definitely not to scale in that pic, as we know that tube is very thick walled! The washer you asked about on the float rod is very clear in this pic. It is directly below the float arm and is what holds the top of the spring. The float I robbed is in a tank exactly like your pic which I believe is slightly different than yours. Mainly on the bottom |
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Post by allan on Sept 29, 2015 2:17:30 GMT
Ok so I was looking at this float and thought the outlet tube was soft soldered into the float. Figured it would be easy to remove so I tried. When I unsoldered it lots of solder fell out but I soon found out it is just a brass sleeve that is place over the outlet tube. Not sure just why it was done this way. The outlet tube is 45% brazed in based on the color of the braze. I wrapped the float seat with wet towels and tried to un-braze the outlet tube. Probably shouldn't have tried but I did. Ended up it wasn't coming out and I am having to drill it out to replace it. If it turns out the ID of the outlet tube is critical I may be adding a restrictor in the new outlet tube. I really think that the float will control it and it won't matter if the replacement tube is larger inside. Got the sides of the base sanded up pretty nice. As you can see here the sleeve did not fill with solder all the way. If it was intended to seal it from corrosion it didn't get it all. Interesting that the tube is steel and the float arm support is brass. Looks like the steel tube must be one piece with the base and the float seat brazed or fused someway to it. That explains why i didn't seem to see any braze or solder were the steel tube meets the bottom side of the base. Sure am learning a lot, hope I can make it work again. It never occurred to me that this would be a corrosion area but I am seeing some fairly deep pitting on the outlet tube especially at the tank base. I have always paid attention to the corrosion on the evap steel to copper joints but never thought about this. But it does stay cold so it has to stay wet I guess. I will look closely tomorrow and check the outlet tube corrosion on the donor float. Great discovery, good knowledge to have ! |
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Post by coldspaces on Sept 29, 2015 3:51:32 GMT
I am not sure why in my mind I thought there was a hole other than the float seat for an orifice. Not shown that way in any of the three Monitor Top manuals. Just don't and haven't work on enough high side floats in my time I guess. Allan I don't think the ID of the outlet tube really matters, they just wanted a heavy duty tube I think. This description of how a high side float works is from the servicing hermetically seal units and explains it better than most things I have read. It is in the Coldspot section. "There is no adjustment in the field on the float valve. The amount of refrigeration is determined by the charge of so2,the capacity of the pump and the thermostat."
So this would tell us the size of the float seat opening isn't as critical as it might seem.The float can only let through what the pump can vaporize and move there. Very little liquid is normally in the high side as most all of it is stored in the evap. Here the bottom has been cleaned up of most all is rust.  After lots of tedious drilling I was able to remove all but the very end of the inlet tube. After I realized it was loose and had moved slightly I pulled it out with a dental probe I modified. I am glad to report that I got lucky and did not drill through to far and hit the bottom of the seat area. After reading on page 270 (12th page down in the servicing high side float info monitortop.freeforums.net/thread/47/servicing-hi-side-floats) in the lower right under plugged line they tell us it normally occurs in the line between the float and the evap. It looks to me like any crud that makes it through the float may build up between the float and the inlet of the tube. Probably kinda flashes out there where the pressure changes so fast. There had to be a buildup of crud after the float, more than just a piece in the float seat considering the pressures I used to try to push through it backwards wasn't getting it opened.  Sure is hard to get a pic down inside of the outlet tube but here the best I could get.  And this one with light sideways over the float seat shows there is still a little build up near it. Will try a little more cleaning with CF-20 on that.  |
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