How to Replace the Piston on a Wagner Power Painter Plus

The piston pumps the paint or stain through your sprayer. It will wear out over time. The length of its life is determined by the type of material being sprayed. When it takes more than about 20 seconds for the suction tube to prime, or if there is excessive material leaking, then it is time to replace the piston.

Let's get started.

REMOVING THE PISTON   1. Remove the motor and handle.

a. Loosen the collar securing the spray tip to pump housing.

b. Remove the spray tip from the paint sprayer.

c. Loosen and remove the lock nut from the pump housing.

d. Slide the motor and handle assembly away from the pump housing.   2. Remove the piston.

a. Remove the piston and spring assembly from the pump housing (it should simply pull out of the housing).

b. Remove the spring from the piston.  

INSTALLING THE NEW PISTON

  3. Install the piston.

a. Install the spring onto the new piston.

b. Install the new piston into the pump housing.  

REASSEMBLING THE UNIT

  4. Reinstall the motor and handle.

a. Install the motor and handle assembly onto the pump housing.

b. Secure the motor and handle assembly with the lock nut.

c. Install the spray tip onto the pump housing.

d. Secure the spray tip with the locking collar.