A gasket is used between two pieces of metal and it will prevent high pressure water from leaking out. Gaskets may or may not always be circular but will usually be flat on both sides. An O ring will always be circular in shape and is used when there is no washer in the pump and there is less water pressure. Both are used for creating a seal between a connection. It's always inportant to remember to change these seals whenever you have had service work done on your pump or it's been replaced. If your gaskets and O rings aren't doing their job of sealing properly, water could and probably will seep into your pump causing you more trouble with the motor and eventually have to replace the motor itself. O rings and gaskets are an inexpensive option to keep your motor dry and free of water and moisture.
