8706012
3.9 Gallon Backpack Sprayer
V4.0
10
For technical questions call 1-800-665-8685
TROUBLESHOOTING
Visit a Princess Auto Ltd. location for a solution if the tool does not function
properly or parts are missing. If unable to do so, have a qualified technician
service the tool.
Problem(s)
Possible
Cause(s)
Suggested Solution(s)
Difficulty actuating the
pump lever and /or pump
handle moves itself back
up.
1. Upper valve plates sticks
2. Piston cylinder outlet
passage clogged
1. Clean or replace valve plate
2. Clean piston cylinder outlet
passage.
Little or no resistance
during repeated pumping
–no pressure.
1. Damaged/worn/dirty
/upper valve plate
2. Worn piston Collar or
cylinder
1. Clean or Replace Valve Plate
2. Replace piston Collar or
cylinder
Upward pumping action is
more difficult and /or
pump handle moves itself
back down.
1. Vent hole is clogged.
2. Lower valve plate sticks
3. Clogged intake filter
1. Clear the vent hole in cap
2. Clean or replace the valve
plate
3. Clean removable cartridge
filter
When the handle is pulled
up it moves itself back
down
1. Valve plate sticking
1. Clean or replace valve plate
Leaks at piston cylinder
1. Damaged /worn /dirty
collar
2. Damaged piston cylinder
3. Damaged piston
1. Clean or replace collar
2. Replace piston cylinder
3. Replace piston
Control switch leaks
1. Connection loose
2. Worn or damaged switch
1. Tighten connection
2. Rebuild or replace the
control switch valve
Spray boom assembly
leaks
1. Connections loose
2. Damaged or worn o-ring
/gasket.
1. Tighten connection
2. Replace o-ring /gasket.
Nozzle assembly leaks
1. Connections loose
2. Damaged or worn o-ring
/gasket.
1. Tighten connection
2. Replace o-ring /gasket.
Leak between pump
assembly and tank
1. Pump clamp loose
2. o-ring worn or damaged
1. Tighten clamp
2. Replace pressure cylinder
o-ring
Hose leaking at tank outlet 1. Hose clamp loose
1. Tighten clamp
