Recently the o-ring seal at the top of the fridge between this tube and the IVC has shown a leak during spray tests. The compression ring had been tightened as much as possible.
Because of this, we decided to replace the o-rings next time it was removed (both for the IVC seal and the main bath seal).
It was very difficult to loosen the compression rings and remove the tube. In the process the tube became scratched.
The shop removed the scratches from the last 2 inches of the tube. This reduced the diameter slightly, but the o-rings are still snug.
The main scratch the shop was concerned with was actually the original seam running the length of the tube, not a new scratch. Mike was of the opinion that it would not keep a vacuum seal in that state (I'm inclined to agree - MF). This “scratch” has been removed.
At this point we still don't have new o-rings (ordered the wrong ones by mistake).
The IVC seal was leak-checked by blanking off the bottom and placing the right-angle connection on the end. It was not installed in the fridge. The old o-ring was used. It passed the leak check.
A little vacuum grease was used on the o-ring.
To protect the tube from scratches as it is raised through the baffles, we wrapped 2-inch wide blue painter's tape completely around the end. The tape extended 1-2 mm past the end and was wrapped tight around the rim. It was not difficult to raise it through the baffles with the tape on it.
It's been noticed that if the compression rings are very loose, the o-ring can jiggle around in the housing, so it is best to loosen the rings only just enough to not compress the o-ring. Then it is held in place and the tube does not contact any metal as it is pushed through.
When raising it through the baffles with the tape on it, it is of course necessary to remove the tape just before pushing it through the top flange of the fridge. At this point someone should hold it while someone else wipes the end with alcohol to remove any residual tape adhesive.
Pushing the tube through the top flange of the fridge presents the most serious danger of scratching the tube. This should be done very carefully. Once the o-ring is reached it should hold the tube centered and prevent any more scratching.
After the tube is pushed through the first o-ring (the one that seals the main bath) the right-angle connection can be positioned over it and it can be pushed through the rest of the way (requires two people of course)
A similar procedure should be used when the tube is removed. Carefully pull the tube down past the top flange, then wrap tape around the end before lowering it through the baffles.