Milking machines are used for five or six or more hours every day, and often much more than that. Broken-down machines or machines operating inefficiently cost in reduced milk volume, time, damaged udders and reduced milk quality. Regular service inspection will allow performance at high efficiency. There are certain maintenance checks that should be performed by the operator at every milking, and every 50 and 250 hours. These include:


  • Wash outside of milk line, receiver jar and trap, claws, and hoses. Empty trap. 
  • Check all rubber parts for holes, tears or water in shells. Replace liners or short air tubes that have holes. 
  • Check vacuum level and vacuum recovery time (no more than two to three seconds after opening one milking unit). 
  • Check vacuum pumps for belt tension (within 0.5- inch from rest position) and oil reservoir. 
  • Make sure pulsators are working. Check with your thumb in the liner. Check each bleeder vent in every milking unit. A paper clip could be used on claw vents, but a finer wire is needed for vents in short milk tubes. 
  • Listen for air leaks.


  • Clean vacuum regulator and moisture drain valves. 
  • Check pulsator and vacuum regulator filters and clean or replace if necessary. 
  • Check short vacuum tubes with vacuum gauge to determine if each pulsator opens and closes fully. 
  • Check stall cocks for leaks and electrical connections for tightness. 
  • Break down receiver jars and weigh jars and clean fittings and gaskets.

Every four to six weeks:

  • Disassemble pulsators and clean air ports and screens. Replace worn parts. 
  • Check each pulsator for proper operation with a vacuum gauge. 
  • Disassemble and clean vacuum regulators and replace air filters. 
  • Flush pulsator vacuum lines. 
  • Check condition of air tubes, vacuum hoses, and milk hoses. 
  • Wash trap inside and out; inspect float.

Every six months:

  • Evaluate the entire milking system. 
  • Replace all pulsator rubber parts, hoses, and air tubes. 
  • Replace all milk hoses. 
  • Replace receiver jar gasket. 
  • Replace rubber hoses and rubber hose nozzles used to wash udders. 
  • Check belts and oiler on vacuum pump(s).

More information.