Troubleshooting
Type B 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. Trigger on spray gun sticks
  2. Pin in the spray pistol sticks
  3. Unit will only spray during pumping
  4. Leakage from the cap
  5. Unit leaks from cap when tipped
  6. Tank is collapsing, cap cannot be removed

Problem 1:
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 2:
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 3:
Unit will only spray while you are pumping

Possible Causes

The pump module (tube) has lost the air pressure head. All air has escaped from the top of the pump module due to an improperly tightened siphon/nut/hose assembly. The washer that comes with the siphon/nut/hose assembly has deteriorated and is no longer sealing properly.

or

The pump module has split or cracked.

Solution:

Check the pump module. If it is split or cracked it will need to be replaced.

If the pump module is not cracked, then tighten the nut at the top of the pump module with the small wrench provided.

If that does not solve the problem, empty sprayer of spraying solution. Unscrew cap (nut) from the top of the pump module and remove. Turn the sprayer upside-down in order to empty the pump module - be careful not to lose the stainless steel ball inside the pump module. Once the pump module is empty, put the stainless ball back inside the pump module and place the siphon tub back into the pump module. Tighten the cap (nut) with the wrench provided. make sure it is very tight.

If that does not solve the problem, replace the washer in the siphon/nut/hose assembly.

Problem 4:
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 5:
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 6:
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.


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