What Are O-Rings?
O-rings are small circular seals that are used in pressure washers to prevent leaks and maintain proper pressure. They are made of rubber or other durable materials and are located at the connections and joints of the pressure washer, such as where the hose attaches to the pump or where the nozzle connects to the wand. The O-ring ensures that water is flowing through the pressure washer at the right pressure and prevents any leaks, which can damage the machine and reduce its efficiency. It’s important to regularly check the O-rings for any signs of wear or damage and replace them as needed to keep the pressure washer in good working condition. It’s common for O-rings to wear out over time, so it’s important to replace them periodically to maintain proper function. A sign that it’s time to replace an O-ring is when there is low pressure or when the quick-connect fittings are leaking.

Common Signs Your Pressure Washer O-ring may be leaking:
- Low water pressure: A leaky O-ring can restrict the water flow and reduce the pressure of the water coming out of the nozzle.
- Leaking water: A leaky O-ring can allow water to seep out of the pressure washer, causing water to leak out of various parts of the pressure washer, such as the pump, hose connections or spray wand.
Here are the general steps to follow to replace a pressure washer O-ring:
- Turn off the pressure washer and disconnect it from the power source.
- Locate the O-ring that needs to be replaced. O-rings can be found in various places on a pressure washer, such as in the pump head, on the hose connections, or on the spray wand.
- Remove the old O-ring by gently pulling it out of its groove or by using a small flat-blade screwdriver or dental pick with a hooked end to gently pry it out.
- Clean the groove or surface where the O-ring sits with a clean rag to remove any debris or old sealant (optional)
- Lubricate the new O-ring with a small amount of silicone lubricant to help it slide easily into place.
- Carefully press the new O-ring into the groove or surface where the old O-ring was located, making sure it’s seated properly (optional for hose ends and nozzle ends)
- Reassemble the pressure washer by reattaching any parts that were removed during the O-ring replacement.
- Test the pressure washer to make sure that it is working properly and there are no leaks.
Common O-ring sizes for quick connects
- 1/4″ – Used mainly for the quick connect at the end of a pressure washer wand where the tips connect to
- 3/8″ – Used almost everywhere else (pressure washer pump end, hoses, etc)
It’s important to consult the manual of the specific pressure washer you have to check the specific instructions and precautions, and always wear protective gear while doing any type of maintenance. It’s also recommended to replace the O-ring with one that is of the same material and size as the original one for best results. O-rings can be purchased at various hardware shops which carry pressure washers or at a local landscape supply store that stocks pressure washers.