That washer goes between the spring and the filter, to keep the spring from digging into the rubber grommet of the filter. We have had many discussions about this washer. Many have never seen it. That's because it often sticks the the old filter and is thrown out. the owner simply installs the filter and spring and goes on their merry way. For years and years. And miles and miles. As you may if you so desire.
To answer your question, it can wait till its convenient.
OK, thanks. I will now use the search to check out the old threads on the topic, because I would love to hear the opinions as to what happens when the spring digs into the filter.
About the spring digging into the filter, i should have added... it doesn't.
Its just inelegant to have a spring pushing on a rubber grommet with nothing in between to act as a buffer, or to spread the load, but trust me it doesn't need to be there.
But you don't have to change all the oil to put it back in. You'll just lose whats in the filter housing, so if it bugs you (it would bug me) I'd drop the housing lose 1/2 cup of oil, replace the washer and be happy.
