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What to Do When a Leaf Blower is Leaking Gas

What to Do When a Leaf Blower is Leaking Gas

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Paul Brown

Is your leaf blower leaking gas? There are a number of issues that could be causing the problem. In this article, we’ll take a look at some common questions related to leaf blower leakage, as well as what to do to repair the leaf blower. 

Common causes of a leaf blower leaking gas include a cracked tank, loose or brittle fuel lines, a cracked primer bulb, a faulty gasket, or a damaged grommet.

Once you’ve identified the problem, you’ll need to replace the faulty part.

But how do you do that? And how do you identify the faulty part in the first place? Read on to find the answers you’re looking for.

How to Figure Out What’s Leaking

As with any small engine, leaf blowers are prone to potential problems such as fuel leaks (source). Structural damage or wear and tear from repeated use are most likely to blame if your leaf blower is leaking gas.

Let’s take a look at some of the leaf blower components that may cause a leak if they become damaged or brittle.

Fuel Tank

One of the most obvious parts to check if you have a gas leak is the fuel tank. If the leaf blower has been dropped, had other tools piled on top of it in storage, or been left out in the weather, the tank may have become cracked. Most cracks will be large enough to spot easily by inspecting all parts of the surface. 

If you suspect the tank is cracked but don’t notice any obvious damage, clean all gas, dirt, and other debris from the outside of the tank. Wait fifteen minutes or so. If there is fresh fuel anywhere on the tank, you’ll know the gas is likely leaking from a small crack in that spot.

If you do find a crack, JB Weld (link to Amazon) is usually the best approach to sealing it. If your leaf blower has a metal tank you may be inclined to weld the cracks but this is generally not advised. The heat required for welding can actually increase the issue of leaks due to heating up the the metal to a point that the solder in the tank joints melts (source).

Fuel Lines

Fuel line problems are perhaps the most frequent causes of leaf blower gas leakage. These can become brittle and crack over time, especially when using ethanol fuels.

Even if the fuel lines aren’t cracked, they may be loose. If you suspect the fuel lines are responsible for the leak, always check the connections before replacing the lines. A faulty connection is a cheaper and less-involved fix than cracked or damaged fuel lines.

If you see fuel leaking from around the fuel line connectors, disconnect them and examine the tubing. If it’s beginning to crack or become brittle, go ahead and replace it. If you are in a pinch you might be able to cut an inch or so of the fuel line off to get rid of the brittle ends but if that won’t work, a replacement fuel line is pretty inexpensive.

And please, if you are still filling your leaf blower with gas from the pump, move to an ethanol-free fuel like Trufuel (link to Amazon). These commercially premixed fuels ensure precise gas-to-oil ratios and eliminate the headaches that ethanol can cause with your small engine. As a bonus, they have a much longer shelflife when compared to fuel pump gas.

Primer Bulb

Most leaf blowers come with a primer, which allows you to pump a bit of fuel to the carburetor for easier engine starting. Of course, the primer bulb is made of soft plastic, so frequent use and exposure to fuel and weather may cause it to become brittle and cracked.

My mother-in-law had a Stihl leaf blower that wouldn’t start and when I examined it I found that the primer bulb had dry-rotted. The engine wasn’t priming because the prime bulb could not get suction.

A gas leak from a damaged primer bulb should be fairly easy to spot. If there is fuel on the outside of the bulb, you’ll know your problem is most likely due to the bulb. Again, if you’re not sure, clean the area and inspect for physical damage. Pump the primer bulb and see if any gas comes out of it.

Gas Cap Gasket

The gasket is what creates a seal around the cap of the gas tank. If the gasket becomes brittle, cracked, or broken, it may allow fuel to slosh out of the tank and leak from the lid.

Note: Some models actually don’t use gaskets. The cap itself is designed to seal effectively.

A faulty gasket is most likely the cause if fuel is seeping from around the gas cap.

You can buy a replacement gas cap for your leaf blower (link to Amazon). Search for your brand. Most models are available.


The grommet is similar to the gasket, only instead of sealing the fuel tank and the lid, it creates a seal between the tank and the fuel lines. This rubber part may become brittle over time, destroying the seal and causing cracks.

If you’ve ruled out fuel tank and fuel line problems but the gas seems to be leaking from the same general area, check the grommet. It will likely be to blame for the gas leak.

How to Repair a Leaf Blower That’s Leaking Gas

Once you’ve identified the problem, it’s time to fix it. But if you’ve never worked on small engines before, the task may seem a little daunting. Have no fear. Most of the repairs you may need to make are fairly simple. Even if you can’t figure out how to do the repair yourself, you can simply take it to any local small engine mechanic.

If you’re going to attempt the repair yourself, let’s take a look at what you’ll need to get started:

  • The appropriate replacement part
  • A basic tool kit
  • Mechanic’s towels, paper towels, or old rags

Just remember to keep the gasoline or oil soaked rags or paper towels far away from any source of fire, including a lit cigarette.

Fix Any Connection Problems

If your inspection of the leaf blower turned up loose parts or poorly connected fuel lines, you should start by fixing these connection issues.

If you’re not sure exactly how and where the fuel lines are supposed to connect, consult your owner’s manual. It may also help to watch a video tutorial. If you can’t find one for your specific model, a more generic tutorial like this one might be sufficient.

How to tell where to correctly connect what fuel line on a weed eater, trimmer, leaf blower or edger

Use the mechanic’s towels, paper towels, or rags to clean any old gas or debris from the area so it doesn’t get inside the fuel system.

You might need to use a basic tool such as a screwdriver or pliers while placing the fuel lines. Make sure not to damage the lines. Tighten them into place until they are well secured to keep them from slipping off again. 

If any other parts seem to have simply slipped out of place, don’t assume you will have to replace them. Try to reconnect them and see if that fixes the problem.

Replace the Damaged Part

If you have to replace a part, it would definitely help to watch a tutorial video before starting. Again, parts you may need to replace to fix a gas leak include:

  • The fuel lines
  • The tank
  • The primer
  • The grommet
  • The gasket

Always make sure you buy the right part for your specific leaf blower.

Replacing the fuel tank, grommet, or gasket may require a bit of disassembly. Depending on the leaf blower, you may have to remove some outer coverings in order to get to the part that needs replacing.

If it’s the primer bulb that’s broken, you may need to remove an air filter to remove the primer bulb, though with some leaf blower models all you have to do is remove the old bulb. The bulb is probably held in place with a couple of screws. Remove the screws, disconnect any fuel lines, and place the new bulb. Make sure to connect the fuel lines to the new bulb correctly.

To replace broken fuel lines, make sure you know which line connects to which part of the leaf blower. Gently remove the old leaky line or lines. You will probably have to remove the fuel filter to remove the line that’s connected to it. Clean the area of dust and old gas. Reconnect the new lines, making sure the connection is secure and the lines are in the right spots.

Final Thoughts

And there you have it. Repairing a leaf blower that’s leaking gas doesn’t have to be difficult. If you can correctly identify which part of the blower is responsible for the leakage, then it’s often as simple as replacing the broken part.

I do understand the frustration that comes with having an issue like this. It’s one of the many reasons that I tossed my gas-powered leaf blower and purchased a 56v Ego battery-powered leaf blower (link to Amazon).

Battery-powered yard tools have come a long way and this thing is a beast. Best of all, there is no carburetor cleaning, no bad-gas issues, or any of the other headaches that come with gas-powered tools.

If you are tired of fighting with gas-powered yard tools, read my review on Gas vs Electric: 6 Reasons To Use Battery-Powered Yard Tools