Lawnmower Leaking Oil Onto The Deck? (We Have A Fix)

Eli Smith
by Eli Smith

When your lawn mower leaks oil onto your deck, you can overwhelm yourself quickly, thinking of all the potential places that could be leaking. For your sanity, your first step will be to calm down and use this guide to help you find a solution. Today, we will give you a step-by-step lawnmower check to prevent oil from leaking onto your deck.

Your first step is to see where the leak has originated. If it is on the deck, it typically is coming from the crankcase seal. You could have also potentially put too much oil in your lawnmower. While checking your lawnmower, look around for any potential holes that may have come from an errant rock. You may need to use your lawn mower’s model number to find replacement parts.

Below, we will get into the details of the step-by-step process of fixing oil leaks that happen upon the deck of your lawnmower.

Do You Need a Mower Repair Service?

Get free, zero-commitment quotes from pro contractors near you.

A Step-By-Step Process Of Repairing Lawnmower Oil Leaks

  • Locate the source of the oil leak
  • Replace parts using the engine model number
  • Follow the repair process
  • Refill the oil

Step One: Locate The Source Of The Oil Leak

When the oil is leaking on your deck, your first step is to find the source. It is dripping from within the mower, so that leaves a limited number of options.

The first option is the upper ring seal. This part is the ring where the crankshaft enters the crankcase. A variety of components typically covers the ring seal. It typically includes the flywheel, which needs a socket wrench and flywheel puller to remove.

If you can remove the flywheel, you should notice a buildup of oil underneath.

Another potential error comes from the oil fill hose or seal, which can potentially leak if a sharp object flies into it. You can repair this with a patch job or a new hose. Seals can be a bit more complicated, but they are relatively simple.

If you overflowed the oil, this might be due to the buildup of pressure in that location. While there is nothing to repair, oil can get everywhere if you have your mower too full. We have a specific guide on what to do if you have too much oil in your lawnmower.

There are many more options for where leaks may occur. Still, the three listed above are what typically happens when you find oil on the deck.

Step Two: Replace Parts Using The Engine Model Number

Companies like Toyota, Craftsman, and Honda all release a new series of lawnmower every few years. Because of this, it is incredibly easy to get overwhelmed by them. Many of them have specific parts for each segment of their release.

As a result, you need to be sure that you purchase the specific parts for your lawnmower’s year, make, and model. Failing to follow through with this can cause significant issues for your repair process.

Be sure that you make this purchase directly from a company’s website. Many third-party vendors lack the expertise and expectations that come with holding replacement parts. They know that the producing company will be the one to pay the price. Tags for this are typically on the side or back of your machine. You won’t see them on the handle.

Step Three: Follow The Repair Process

If you have already removed the flywheel at this point, the remainder will be reasonably simple. The owner’s manual will take much of the guesswork out of it, but you will need to pry the seal off. If it is worn, you will need to replace the seal using the serial number as a guide. Be sure that you have the exact size required. Most of this should be solved by comparing serial numbers.

If you need to replace a dipstick tube or seal, it’s a matter of finding an identical oil tube and removing the two top covers for the gasoline tank and the lawnmower.

Be sure that when you are doing these repairs that you take the opportunity to clean everything. Also, do not do this while the spark plug is connected or the engine is hot.

Step Four: Refill The Oil (Not Too Much)

Most lawnmower repair processes involve you tilting the lawnmower onto its side. As a result, it is pretty standard for oil to leak out onto the floor. Because of this, you may consider placing a sheet of cardboard below your mower.

However, a standard error that causes oil on the deck is putting in too much oil. Many times, lawnmowers don’t even take a single quart. Check your owner’s manual and dipstick for further information on the right level of oil.

How Do I Avoid Oil From Getting On My Deck?

If you found that your oil is leaking regardless, it may be related to some bad habits. It includes tipping your lawnmower on the wrong side. Always be sure that the carburetor is facing upwards.

Typically, carburetors are black and connected to the side of the lawnmower. In some cases, lawnmowers are unable to start if you flip the carburetor side down.

Mowing at steep angles can also cause the same issues for the same reasons. If you have incredibly steep locations, try and see if you can’t use a weed wacker for those. Lawnmowers are best for larger areas.

Do You Need a Mower Repair Service?

Get free, zero-commitment quotes from pro contractors near you.

Related Questions

What If My Lawnmower Is Leaking Oil From The Bottom?

The most common issues related to oil coming from the bottom goes back to the oil tank or gaskets related to this. This situation is where the potential of rocks flying up and puncturing your tank is high. You will still want to look up the same information using serial numbers and repair processes through the owner’s manual.

What If My Lawnmower Is Leaking Oil From The Valve Cover?

If you can smell burning oil or see a loose valve cover gasket, this is another potential location for leaks. In some cases, it can come from loose bolts on the valve cover. Try and test this repair out before going any further.As with any repair process, check your owner’s manual for details on the repair process. Never start the repair process with the engine running.You will need to remove any bolts on the top of the valve cover to start the repair process. After lifting it off, check to see if the gasket along the side is worn. That is the most likely culprit when it comes to oil leaks.

Can I Use Stop Leak Products For My Lawnmower Engines?

Products like BlueDevil Oil Stop Leak feel like an easy solution for small engine oil leaks. But are they safe for smaller engines? Typically, the answer to that question will depend on the product’s claims. For example, Bar’s Leaks Stop Oil Leaks products claim to be for small engines.Always check on the side of the bottle before assuming that something will work. It doesn’t mention that it can be used for small engines, avoid using it. There are various product options available, so search around at your local hardware store for details.

Eli Smith
Eli Smith

I'm a guy who becomes the expert of whatever I stumble upon, writing-wise. I've written tons about cool home products, home improvement, and smart technology in the home. I'm also the proud father of a kiddo born on new years, making my holidays very busy.

More by Eli Smith