This morning it was past time to service my Micro Casa a Leva group. I disassembled the group like I have done many times before, and then I cleaned everything very very carefully. After applying the normal silicone grease, I put the piston back into the group and fastened down the two Allen screws that hold the piston and lever assembly in place.
I turned on the machine and let it warm up. When I raised the handle to flush the group a bit, water came pouring out the air exit hole in the back of the group. This was very strange, because the seals seemed in very good condition when I had examined them. Strangely, the water leakage stopped. I let the machine stay "up to pressure" for about half an hour, and no more water leaked. I disassembled the group and reassembled it. I powered up the machine, and there was no water leaking past the piston at all this time. The question is, why did it leak after the first disassembly and reassembly?
Perhaps I somehow got something into the grease that was stuck against the seals? The cylinder wall was ideal. I have a towel that can be pulled through the group bore to clean it. I had cleaned it this way.
Have others had anything like this occur?