How to Troubleshoot a Lesco Backpack Sprayer

Pump Lever Is Hard To Move

• 1

  Take off the pump lever and clean the bushings. Lubricate the bushings with grease.

• 2

  Remove the pump assembly from the sprayer. Clean the cylinder walls of the pump and the pump piston.

• 3

  Check the piston collar for swelling from long-term use. Replace the collar if it is swollen. Lubricate a dried-out collar.

Repeated Pumping Produces No Pressure

• 4

  Check the valve plate for a dirty or defective valve. Check the valve O-rings for leakage.

• 5

  Remove the pump assembly from the sprayer. Examine the pump piston and collar for excessive wear and replace the part, if necessary.

• 6

  Examine the pressure regulator for a leaking seal and replace the seal, if necessary.

Pumping Becomes Increasingly Difficult and Tank Walls Constrict

• 7

  Determine that the correct vented tank cap is installed. Check the vent hole for clogging.

• 8

  Examine the valve plate for a stuck valve.

• 9

  Check the intake hoses for blockage. Clean the hoses and tank.

• 10

  Inspect the inlet screen underneath the pressure regulator if the pump handle keeps retracting when it is pulled upward. Clean the inlet screen with detergent and a small brush, if necessary.

Leaks

• 11

  Evaluate the condition of the piston collar and the piston if leakage occurs inside the cylinder.

• 12

  Evaluate the condition of the cylinder O-ring and the pressure cylinder O-ring if leakage occurs outside the cylinder.

• 13

  Check the shut-off valve on the wand for wear or damage if liquid leaks from the end of the wand.