Troubleshooting:
Type A Backpack Sprayers

The following describe common problems and solutions for the following sprayer models:

The following problems are listed, along with their causes and solutions:

  1. Unable to build pressure/fluid leaks from wand when sprayer is pumped
  2. Trigger on the spray gun sticks
  3. Pin in the spray pistol sticks
  4. Unit not building pressure after extended use
  5. Leakage from pump module
  6. Leakage from cap
  7. Unit leaks from cap when tipped
  8. Leakage from clamps near pump module
  9. Brand new sprayer has leaky hoses
  10. Tank is collapsing and cap cannot be removed

Problem 1:
Unable to build pressure or fluid leaks from the wand when the sprayer is pumped.

This problem can happen when the sprayer is new or when the sprayer has not been used for a long time. When you pump the sprayer, the sprayer does not build pressure and/or fluid leaks from the wand. This is a common problem.

Cause:

The check valves in the pump are stuck and/or there is an air lock in the unit because of differences in pressure.

Solution:

Squeeze the trigger on the spray gun to release air, then pump the sprayer vigorously several times. This will break the seals and allow the fluid to pass.

Problem 2:
The trigger on the spray gun sticks

When you squeeze the trigger on the spray gun, it sticks and is slow in returning to the shut-off position when you release the trigger.

Cause:

The O-rings have deteriorated because of chemical attack.

Solution:

Replace the O-rings in the spray pistol and on the brass spindle inside the spray gun (Order KIT 20). Note that if these O-rings have deteriorated, you should also check and replace the other O-rings and seals in your sprayer before leaks or other problems occur.

Problem 3:
The pin in the spray pistol sticks

The pin in the spray pistol sticks when pushed. When you release the trigger, the pin does not rise to shut off the flow.

Cause:

The O-rings and washer on the spindle inside the spray pistol have deteriorated from age or chemical attack.

Solution:

Unscrew the cap on the bottom of the spray pistol. Push out the brass spindle and replace the O-rings and washers (Order KIT 20).

Problem 4:
Unit is not building pressure after extended use

You have been using your sprayer for some time. When you pump the unit, you can't build pressure. If you stop pumping, very little liquid leaves the wand.

Possible Causes:

The O-rings and the check valve on the pump module have been attacked by chemicals and are no longer sealing. There are two O-rings: one large and one smaller, plus one check valve.

or

The pressure chamber has expanded due to pressure and/or chemical attack.

Solutions:

Change the O-rings and seals in the pump module (Order KIT 12). If these seals have deteriorated, you should change out all rubber seals in the unit.

If this does not solve the problem, you should replace the pressure chamber (Order KIT 9).

Problem 5:
Leakage from the connection between the pump module and the sprayer

The unit is leaking fluid from the area where the pump module is connected to the sprayer.

Cause:

The O-rings have deteriorated.

Solution:

Replace the O-ring and seals in the pump module (Order KIT 12). If these seals have deteriorated, you should change out all rubber seals in the unit.

Problem 6:
Leakage from the cap

Fluid is leaking from the cap, which should be sealed with the tank.

Cause:

The cap may be loose or fluid might be pulled through the cap because of capillary action.

Solution:

Oil the gasket using any type of oil 30 wt. This will stop the passage of fluid.

Problem 7:
Unit leaks from cap when tipped

When the unit is tipped or falls on its side, fluid leaks through the center of the cap.

Possible Causes:

The check valve may be dusty, dirty, or coated with foreign matter.

or

The check valve may have deteriorated because of chemical attack.

Solution:

Unscrew the cap and examine the check valve. If it is dirty, clean it, oil it, and replace into the cap. If it is deteriorated, replace it.

Problem 8:
Leakage from clamped area near the pump module

The sprayer is leaking from the area just below where the large metal or plastic clamps are located - where the pump module and pressure chamber enter the unit.

Possible Causes:

This hose clamp is loose.

or

The O-ring has deteriorated.

Solution:

Tighten the hose clamp. If that does not fix the problem, check the O-rings. Replace them if they have deteriorated.

Problem 9:
Brand new sprayer is leaking

Your sprayer is brand new and is leaking from where the hose connects to the sprayer and/or where the large hose clamp holds the pump module and chamber in place.

Cause:

The hose clamps are not fully tightened at the factory to ensure a longer life. Please see the orange tag on the side of the unit.

Solution:

Tighten the clamps with a screwdriver.

Problem 10:
Tank is collapsing and cap cannot be removed

The unit is working properly, but the tank is beginning to collapse. When you try to remove the cap, you cannot pull unscrew or remove the cap from the unit.

Cause:

The sprayer has created a vacuum because the vent hole in the cap has become clogged with dirt or debris and is not allowing air into the tank.

Solution:

Push a small wire through the vent hole to allow air into the tank and release the vacuum. Remove the cap. Clean the vent hole and the check valve. Oil the check valve then re-install into the cap. Replace the cap onto the sprayer.


©2005 SP Systems, LLC