A sump pump leaking oil means that your pump is at risk of lacking lubrication in key areas of the motor while running. Oil Leaks of any size are serious and should never be ignored. Sump pump oil in the pit, basin, drain lines or on the side of the pump is a sign something is wrong! Leaking oil also means that water may be leaking into sensitive areas of the pump or cause the pump to burn out.
Sump Pump Failures
Pedestal sump pumps are mounted on stands and more open than others so it is easier to inspect the pump and diagnose where the oil is coming from. You can merely run your hands over parts of the pump or visually inspect for oil puddles and drips.
If you have a submersible sump pump, then it will be harder to find the source of the oil. Usually, the first sign that something is wrong is oil droplets floating and creating a sheen on the top surface of the water above and around it.
The pump should be unplugged and removed so it can be inspected for leaks. If the oil is not coming from the pump, then look around your basement for another source.
Step by Step Instructions
If you find oil in your pump pit we recommend the following:
- Removing the pump from the pit and drying it
- Locate the source of the leak
- Repair the leak and refill oil
- Reinstall the pump and test

What Kind of Oil Do Sump Pumps Use?

Most sump pumps are factory sealed to prevent leaks and overheating but if you experience a large leak you might need to add more oil.
The best kind of oil to use in a sump pump is ISO30 turbine oil or 5W30 motor oil. We recommend WD-40 3-in-One Motor Oil, it is not too expensive, it can be used with other around the house tools and machines plus a bottle will last a long time. If you are unsure about the right type of submersible pump oil check your manufacturer’s guidelines.
Do Sump Pumps Have Oil?
Yes! Sump pump (and most other motors) use oil to lubricate and keep things on the inside running properly. Some pumps use different types of oil like turbine oil so make sure to check the owners manual so you buy the correct kind.
Sump Pump Oil Changes
If your sump pump is running low on oil after a leak you may need to add more oil. A good sump pump should never need an oil change like your car – but if some leaks out you may need to refill it with an ISO30 turbine oil to prevent overheating.
Oil in Sump Pump Well Pits
Finding oil in your sump pit almost always a sign of a problem – you just have to find it. Locating the source of your oil leak is easy most of the time. All you need to do is disable the pump, remove it from the pit and inspect the pump and lines for the leak.
Sometimes the oil may actual be enter the pit from the groundwater – not from your pump. If this is the case you will need to give your pit and pump a good cleaning.
Avoid Environmental Contamination
If your sump pumps is leaking oil or oil contamination from another source, then it is pumping oil contaminated water outside.
Oil Spill Warning!
Oil is not good for your lawn or the streams and other natural features around your home. Make sure to properly clean up all spills ASAP – even if they are in your basement!
If you have nearby oil storage for heating, then this can be a source of contamination if a tank starts leaking.
Failed Seals or Housing
A leak in both a submersible and pedestal pump can be caused by a cracked or damaged seal or gasket. A gasket is usually easy to find and fix.
If the housing is cracked, then a completely new pump assembly will need to be purchased and installed. It is best to leave the major repairs and the sourcing of materials to a sump pump professional.
Losing Oil and Pump Failure
A small leak can still do a lot of damage to your pump. When a sump pump is not getting enough oil for lubrication, it has to work harder to do the same job. The harder your pump has to work the sooner you will find yourself having to purchase a new one.
If a leak is positioned a certain way, then there is a risk of water getting into parts of the pump that are not meant ever to have contact.
Corrosion and electrical shorting can result which means during a big storm you may find yourself without any pump at all to take care of the rising water levels.
Oil Leaks that Come Back
If you try to fix a leak, and it comes back, then you are going to have to take it to the next level. If you haven’t got professional help at this point, then now is the time.
You don’t want to start chasing problems and fixing them only to realize you could have just got an entirely new sump pump installed without all the work.
What type of oil goes in a Zoeller Pump?
Zoeller sump pumps use Dielectric oil. This is a lighter mineral oil that works well inside motors near water.
Keep in mind your normal bottle of mineral oil can’t be used as a replacement – you need to use special Dielectric oil.
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