crwdns2893792:0crwdne2893792:0 John 680 ,


When I selected  a large mine  (a B60) would pump about 6 ounces, and then the rest would flow back to the tank through the vent/overflow line.  None of the regular repairs helped.  I tried  descaling, cleaning needles, banging it around every way conceivable, blowing air into both the holes on the vent, and removing and cleaning the top check valve.  Then I took the bottom off and saw there is a simple check valve on the pump discharge.  It has a rubber nipple in it which I pried out with tweezers after removing three screws and splitting the housing. There were blisters on the rubber nipple preventing it from operating properly.  I punctured the  top layer of rubber on the blisters from the outside with a sewing needle and squeezed out the trapped water.  Reassembled the unit and now it is working fine.