Why is My Weed Sprayer Pump Not Working?

A malfunctioning weed sprayer can quickly become a problem, throwing a wrench into your plans and preventing you from completing the tasks on your to-do list. After all, it’s tricky to evenly and efficiently apply a liquid weed control product without the sprayer.

So, what should you do if your weed sprayer pump isn’t working and the weed control application process is on hold? Try these troubleshooting tips.

4 Reasons Why Your Weed Sprayer Pump Isn’t Working

Pump sprayers are relatively simple systems, but sometimes, pinpointing the culprit behind your non-functioning pump sprayer can be tricky. Some problems, like replacing a filter or broken component, are easier than others, like finding the tiny leak in the spray hose.

But before you throw in the towel, here are a few reasons why your sprayer pump isn’t working (and how to fix them):

1. Dirty or Damaged Filter

A dirty or damaged filter is one of the most common culprits behind weed sprayer pump functionality issues. Most pump sprayers feature a filter or screen that removes sediments and ensures the pump functions smoothly.

However, when the filter becomes clogged, rusted, or damaged, the pump might not be able to generate the pressure necessary to push the liquid through the filter. To remedy the problem, you’ll need to check the filter.

Unscrew the hose and examine the filter for debris or damage. If there is debris clogging the filter, rinse it thoroughly with warm, soapy water and use an old toothbrush or scrubber to remove stuck-on debris.

If the filter is damaged, you’ll need to replace it. You can usually find the correct replacement part on the manufacturer’s website, but if you’re unsure which part you need, check the owner’s manual for the exploded parts diagram.

2. Low Fluid Level

While this one is painfully obvious, it’s surprisingly easy to miss, especially when the liquid inside the tank is clear, or the tank is opaque. If the fluid level in the tank gets too low, the pressure will drop, and the sprayer might be unable to pull liquid into the spray hose.

So, check to ensure the fluid level in the tank is sufficient. If it’s too low, add more of your solution to ensure the system functions properly.

3. Broken Components

A busted component can also be the culprit causing functionality issues with your pump sprayer. A broken clutch or impeller can affect the system enough to prevent it from working at all, so if the above problems aren’t the culprit, check for damaged components.

A broken clutch can present itself in two ways: the system might not work at all, or the pressure might be abnormal. The clutch is essential to the system’s function, so if you suspect it might be the problem, you’ll need to check for damage or corrosion.

You can easily flush sediment from the clutch by filling the sprayer with a mixture of vinegar and warm water. Let it sit for about an hour, then dump it out and flush the tank to clean it. However, if the clutch is broken, you’ll need to purchase a replacement to get the pump working again.

Alternatively, it could be the impeller that is causing the problem. The impeller is the part inside the system that spins to generate pressure, which allows the nozzle to dispense the tank’s contents at high pressure.

If you suspect the impeller isn’t working, you’ll need to examine it. Disassemble the pump to expose the impeller. If you’re unsure how to do this, consult your owner’s manual. Once the pump assembly is disassembled, examine the impeller for damage or lost seals.

A lost seal can prevent the pump from working, so if it has magically disappeared, you’ll need to replace it. Once you replace the seal, it should remedy the issue. However, if the seal is intact, you’ll need to check for proper function and corrosion.

First, try turning the impeller to ensure it works smoothly. If it’s broken, you’ll need to replace it. If you find corrosion, clean the impeller with warm water and vinegar solution. Apply it to the impeller with a cloth to remove buildup and debris. You can use an old toothbrush dipped in the vinegar solution to help remove stubborn gunk.

4. Leaks

When your pump sprayer develops a leak, it won’t be able to generate pressure. So, this can do one of two things: prevent the system from working at all or cause a significant drop in pressure. When you suspect a leak is the culprit, you’ll need to do some sleuthing to find the exact point of the leak.

Here are a few places to check:

  1. Check the cap to ensure it’s on firmly and the gasket is seated properly. If the gasket is worn or damaged, it can allow air to leak and prevent pressure from building. Replace the gasket as necessary, but sometimes tightening the cap will do.
  2. Check the shut-off valve for leaks. If you find a leak, try tightening it to stop the leak. If that doesn’t work, you’ll need to replace the shut-off valve.
  3. Examine the hose for leaks. If the hose is screwed on loosely, it can affect the pressure generation within the tank. Tighten the hose onto the tank to remedy the problem. If that doesn’t work, check for broken pieces and replace them as necessary.
  4. If the leak stems from the end of the spray nozzle or wand, it indicates a broken or damaged O-ring. You’ll need to replace the O-ring to stop the leak.
  5. Check the gasket on the filter, as poor seals and improper seating can lead to leaks. To help encourage a leak-free gasket, coat it with a lubricant.
  6. Check the condition of the spray hose. If there are pinhole leaks, you’ll need to replace it. Spray hoses often wear out quickly, especially if they don’t have extra support, like embedded wire or a plastic coil. Replace the hose as necessary.

5. Power Issues

Many pump sprayers are manually-powered, requiring you to pump the handle to build pressure in the tank for spraying. However, there are numerous battery-powered and gas-powered models out there.

If you have a battery-powered or gas-powered pump sprayer, ensure the battery has plenty of charge or gas in the system. With battery-powered systems, you’ll need to ensure the battery is sitting correctly on the contacts in the battery compartment to allow power to flow from the battery to the system.

With a gas-powered system, you’ll need to ensure there’s plenty of fuel and there aren’t any issues that could prevent the fuel from getting where it needs to go.

Gas and battery-powered systems can be more complex than their manual-powered counterparts. Since there are quite a few models out there from different manufacturers, we recommend consulting the owner’s manual and troubleshooting guide for help specific to your pump sprayer model.

Contact the Manufacturer

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If all else fails, check in with the manufacturer. They may be able to offer specific information pertinent to your particular pump sprayer model, which may help remedy the leak.

So, if you can’t figure out why your pump sprayer isn’t working and don’t want to replace it quite yet, contact the manufacturer for help.

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