Swissmex SW503 Operating Hints & Servicing Tips

Croplands Swissmex SW503 sprayer in use

To help you get the best performance from your sprayer and for your own safety, please read and observe the following information.


  1. Before using, filling, or cleaning any sprayer, read the operating instructions.
  2. Read and follow all instructions of chemical suppliers.
  3. Wear protective clothing, respirator, gloves, eye protection etc, when using, filling, or cleaning the sprayer.
  4. Keep connections well tightened to prevent leaks.
  5. Never fill the sprayer with hot liquids. Max temp = 30 C / 86 F.
  6. Do not use the sprayer to apply caustic, corrosive, or flammable solutions.
  7. Before cleaning or servicing the sprayer allow all pressure to escape. Always wash the sprayer after each use with plenty of fresh water.
  8. Do not leave any sprayer in reach of children or persons not qualified to use it in the correct fashion.
  9. You might like to consider purchasing a Pakman Foam back protector for extra comfort while you are spraying.


  1. Remove cap.
  2. Always use the strainer when filling the tank up with liquid.
  3. Mix solution in a separate receptacle/jig, following the manufacturer’s directions on the container.
  4. Pour pre-mixed solution into sprayer and put cap on.
  5. Place the sprayer on your back and pressurise the tank by pumping approx. 25 times
  6. You will need to pump once every 3 or 4 seconds to maintain the desired spraying pressure.
  7. Always oil the seal on the cap of the unit as well as the check valve, as this will extend the life of the seal and is important for obtaining a proper seal with no leaks.
  8. A unit that has been used with herbicides should never be used to spray insecticides unless the sprayer has been properly cleaned and all the chemicals neutralised. Failure to do this could cause you to kill plants that have been sprayed. Consult the manufacturer of the chemicals you are using to obtain proper instructions.


  1. Allow pressure to escape. Remove cap and pour out any remaining solution, then rinse all parts thoroughly with clean water.
  2. Leaving approximately 2-2.5 litres of fresh water in the tank, pressurise and flush the pumping system by depressing the trigger for at least 2 minutes, then drain all remaining water.
  3. Carrying straps will not absorb chemicals. In the event of a formula spill, however, tank and straps should be properly cleaned with fresh water to eliminate all possible risk of skin irritation.
  4. Always store the tank clean and empty in a dry, shaded location.


  1. Remove the locking pin at the end of the pump handle and the nuts and screws that secure the pump lever.
  2. Remove the module from the unit.
  3. To inspect or change the valve plates or the piston sleeve, just unscrew the module, change the valve plates and/or the piston sleeve if necessary and place the module again, making sure that its exterior notch aligns with the groove of the chamber. This way the little module windows will match with the chamber outlet.
  4. Place the pump lever in position with the piston and the locking pin.


Download a PDF


SWISSMEX SW503 PARTS DIAGRAMParts Breakdown drawing for SW503 Swissmex Sprayer



Download a PDF


Swissmex Knapsack 15 L Orchard Spot Sprayer & Garden Sprayer