There’s nothing more frustrating than walking into your garage or shed and seeing your beautiful chainsaw with that little dew drop of oil just waiting to fall and wreak havoc on your nice workbench or floor.
Leaking oil is not an uncommon problem when chainsaws are stored for any length of time.
Here is a little prep work that will save you time in solving chainsaw oil leaks.
Wipe the bottom of the chainsaw to remove any trace of oil leakage. Now place a clean sheet of cardboard down and let the chainsaw sit on the cardboard in the upright position.
In a day or two, you will be able to see where the leak is coming from more clearly, and that makes the repair a lot simpler.
Remember that chainsaws leak bar oil as part of their design while running. However, there should be no oil leaks when the chainsaw is not in use.
Let’s take a look at why this happens and what you can do to prevent it.
Main Reasons A Chainsaw Leaks Bar Oil
It is important to understand that the chainsaw is designed to provide a flow of chain oil to the bar and chain while the chainsaw is operational.
Consider it a controlled oil leak, and it is good practice to check that the chain is being properly lubricated when the saw is running.
The easiest way to check this is to position the end of the bar a little way off some paper or a piece of wood and run the saw. You should see a light spray of oil on the paper.
There are a number of situations that may cause an oil leak, but let’s find out how to store a chainsaw so it doesn’t leak oil.
Overfilled Oil Reservoir
Most chainsaws are designed so that the gas and the oil tanks have similar capacities in terms of ‘run time.’ This should result in the gas and the oil tank running empty at pretty much the same time, provided they were both full before the chainsaw was run.
The danger is overfilling either tank. The oil tank is more susceptible to being overfilled because of its relative size, and the result is your chainsaw leaking oil onto your clean shelf or floor.
The typical scenario is at the end of working with the chainsaw, the oil reservoir is filled and the cap refitted.
The whole chainsaw is warm from being used, and the new oil will expand as it is warmed by the machine. As the cap is fitted, the oil can only escape through the ports and onto your floor or shelf.
A similar situation also arises when the tank has been filled and the ambient temperature increases, which forces the oil to escape through the ports.
A simple solution to stop any oil from leaking out is to make sure that there is a small gap between the level of the oil and the top of the tank.
And make sure to never go beyond the maximum fill level.
There is a tendency to fill the oil reservoir to the maximum because of the threat of running out of oil before the gas supply has ended.
It is never a good idea to allow either the gas or the oil tanks to run dry so fill both tanks often while using before your chainsaw’s performance suffers from debris that can cause blockages in either system.
It is also important to remember that the fuel tank can create a leak in much the same way as the chain oil tank.
Over-Pressurized Oil Tank
Changes in pressure in the oil tank should be controlled by a one-way valve normally fitted to the cap of the oil tank.
The valve allows ambient air to enter the tank to prevent any vacuum from forming inside the tank.
However, a problem arises when the ambient temperature changes from cold to hot in a short time.
The oil expands, but the one-way valve will create a pressure buildup, and the only place for the oil to go is through the oil ports causing the chainsaw to leak.
There is a simple solution to this problem, and that is to unscrew the oil cap a little when storing the chainsaw. This will avoid any pressure buildup in the tank. Remember to tighten the cap when you next use the saw.
The Oil Cap Might Need To Be Replaced
If your chainsaw leaks oil, the most common component failure is the oil cap. So it’s worthwhile to look at the cap and check that the ‘O’ ring is in good condition.
The cap will wear out with heavy and constant use or if it has been incorrectly fitted, so check it out first.
Plugs Need Tightening
Most chainsaws have a small plug in the oil system, which is located next to the exhaust muffler. The plug is small.
On a Stihl chainsaw, it is a 6 mm or 1/4 inch set screw.
Oil leaking from the plug will be obvious if you shine a light down the side of the muffler and see oil or oil-soaked sawdust.
You can locate the leak by checking the position of the oil leak on the clean piece of cardboard you fitted under the chainsaw. You will need to take the muffler off to replace the plug.
Please do not be tempted to replace the plug with a standard 1/4-inch or 6 mm set screw. Get the proper part. An incorrect size plug can prevent the correct amount of chain oil from reaching the bar.
Vacuum Relief Valve
You will need to remove the bar to check on the vacuum relief valve. The valve is springloaded and allows air into the oil tank to compensate for the volume of air leaving the tank.
Once oil outflow stops, the spring closes the valve, and a seal is restored.
Dirt or sawdust entering the valve will cause it to leak. Take care to clean the valve thoroughly, and this should prevent any more oil from leaking out from the vacuum relief valve.
Storage Environment
Heat changes the viscosity of oil and could cause it to leak, especially if stored in a shed that’s in a hot climate like Florida. Oil is temperature sensitive.
Chainsaw guide bar oil, described as summertime oil, is thicker and heavier and made to operate in hot conditions.
Winter chain oils are thinner and provide lubrication in cold conditions.
The chainsaw is often packed away with the winter bar oil left in the tank at the end of the winter season. As the temperature rises during summer, so does the possibility of the oil leaking out of the tank.
Cheap Bar Oil
Some bar oil is cheap and more like motor oil, whereas you want a thicker oil that is more like the consistency of syrup if you are running a powerful gas-powered chainsaw.
In addition, you need a high-viscosity oil to deal with the speed, force, and heat that a gas-powered chainsaw develops.
You do want the oil to be a ‘high tack’ oil to keep at least some oil on the chain when it is moving at high speed.
A thinner low viscosity oil is suitable for lightweight chainsaws like corded or smaller battery-operated saws.
I’ve seen people suggest using vegetable oil or canola oil on chainsaws, but while they may have achieved good results, I can’t believe it makes any sense to skimp on a few dollars and risk destroying your chainsaw.
Chain Debris
Dirt and sawdust do collect inside the saw, particularly around the drive cog, and this can build up to such an extent that it dams up the oil lines.
There are two results from this. The first is that there is a reduced flow of oil to the chain from the oil outlets when the saw is operational, and secondly, when the chain is not running, the oil that has soaked into the debris around the cog will start to leak out.
The easy solution is to remove the chain and the bar and clean out the saw thoroughly.
Short Term Storage Dos And Don’ts
Here are some tips that may help keep your chainsaw from leaking oil when in storage.
Store The Chainsaw With The Chain Brake Engaged
While some suggest that storing the chainsaw with the brake on reduces the stress on the spring, it doesn’t seem to make any difference.
Most chainsaw manufacturers make no recommendation about the brake being engaged while the saw is in storage, so it is a personal preference.
Store The Chainsaw On Its Side With Oil Cap Up
Storing your chainsaw in this position will prevent oil leakage from the cap, which is the most common cause of chainsaw oil leaks.
Another advantage of this position is that it allows for the filler cap to be slightly cracked open, reducing the risk of pressure buildup in the tank.
Store Hanging From Bar
This is not a good way to store a chainsaw, even if there is a handy hole in the bar.
All the weight of the saw is carried by the bar, which creates excessive pressure that the bar is not designed to carry—in addition, hanging by the bar results in fuel and oil filler caps typically being below the normal fluid levels of the tanks.
This situation will promote leaks if the tanks have not been drained.
Long Term Storage
Long-term storage is about draining the oil and gas tanks.
Once the tanks have been drained, it doesn’t really matter if you store the chainsaw in a conventional way or vertically, as there is no liquid left in the machine to cause any problems.
The ideal storage place is out of the sunlight and preferably with less extreme temperature changes.
Keep the saw indoors and away from the weather and any damp conditions.
Drain Oil And Gas
You can drain the gas into a container covered by some cheese cloth if you want to keep it for next season.
Be sure to clear the carburetor as well since a small amount of gas will hang out in there.
You can do this by running the chainsaw without any gas in the tank. It will sputter out, do it again and repeat one more time. You can leave the gas cap off for a little bit to allow everything to dry thoroughly.
Next, drain the chain oil tank, remove the spark plug, and place a couple of drops of chainsaw oil in the cylinder.
Now is a good time to give the spark plug a good cleaning with a wire brush while you have it out.
Pull the starter cord a couple of times to ensure the piston has been well lubricated and replace the sparkplug.
If All Else Fails
Try storing it in a hard shell case or on an old cookie sheet to make cleanup from oil leakage easier.
Final Thoughts
Most Chainsaw manufacturers provide guidelines on how to store a chainsaw, so it doesn’t leak oil, as well as tips on long-term storage.
There are personal preferences that come into play. Personally, I never drain my saws, but then I live in a subtropical climate, but if I had to contend with huge variances in temperature, I would drain my saws after winter.
Draining the saw is a great opportunity to have a good look over the condition of the saw and to check on any issues that may become a problem in the new season.
Frequently Asked Questions (FAQ):
Why does my chainsaw leak bar oil when stored?
The most common issue to cause a chainsaw to leak oil when stored is a malfunctioning filler cap. Other reasons may result from a blocked pressure release valve or a loose plug in the oil pipeline.
Is it normal for chainsaws to leak oil?
While a chainsaw is operational, it is normal for oil to pump from the tank onto the bar to assist in keeping the chain performing at an optimum condition. Once the chainsaw has stopped working, there should be no more oil leaking from the oil reservoir.
Can you store a chainsaw vertically?
Yes, it is possible to store a chainsaw vertically. However, in doing so, it is recommended that the gas and the chain oil tank be drained to avoid any possibility of leaks. Remember that the carburetor also needs to be drained.
