Dear friends, I am a bit in trouble. This morning I loaded my Jobo 1520 (one 135/36 roll) in my changing bag and after taking it out of the changing bag I checked as usual that it was correctly closed. During treatment, during the washing after development I noticed the water in the upper basin of my Jobo CPP-2 had a yellowish tinge, and yes, I noticed after that that I could not recover all the washing water I poured in it. I took the tank and once again pressed the orange collar very firmly. It seemed to me that it was perfectly tight. I went on with processing thinking that the tank was okay and maybe the leakage was only during the discharge phase (a gasket somewhere, worrying anyway) so that I could save the film inside the tank. When I arrived at the bleach phase (dark violet) I had the definitive confirmation that the leakage was actually occurring from below the orange collar of the tank. I observed the tank carefully before opening it: nothing unusual. I did some test with water: water leaked from below the collar. I opened it, took the totally spoiled film away, did some more tests. No leakage. I tried with the reels in both position (reversed vertically), no leakage. I tried a test with some coloured liquid that allows to see where the leakage occurs, it came to my mind that red wine could be good for this (the blasphemy apart). So I sacrificed 140 ml of red wine, and again, after 10 minutes, no leakage. Now I don't trust my tank, or myself, anymore. Making a presoak phase would allow me to measure the recovered water and see if there is some leakage before actually pouring the first developer. So I am planning, since now on, to use a 1 minute presoak with water at treatment temperature. Is there anything I should be aware of? Possible negative side effects? Should I extend, or shorten, my development time? I use Fuji film (Sensia or Astia). Thanks for any help Fabrizio PS I don't have any instructions for loading the Jobo 1510. I presume the reel can be in any position, the small cylinder inside the reel must go with the broad base on the bottom of the tank. The three red dents on the orange collar must coincide with the three spaces on the tank cover. The orange collar must be pressed firmly downward and it will make the tank watertight. I can't imagine what have I done wrong.