Symptoms

  • Following  a PM service pneumatic pump appeared to be working; cycled without pump head attached but at required more than minimum pressure to start
  • Pump primed with ethanol, cycled with product piping loose after pump head but apparently jammed when the glands were tightened
  • Removed the pump head, isolator and case and the pump would not cycle, appeared to be jammed in the retracted position

Solution

  • Darko suggested that the fault may be a defective pilot valve (P-1-A-32) from the air motor
  • Replaced the new pilot valve with the old one from before the PM service and the pump started behaving normally
  • James Lisofsky says that the new pilot valve can be adjust using the screw at the end of it to allow it to operate properly