Join Date: Sep 2008
Location: Fruitland Park,Florida
You can buy o-rings at auto parts stores, hardware stores, & harbor freight. Bring the part that lost it's o-ring with you so you can test fit it.
If o-ring is an unusual size, you might be able to find it online @ McMaster Carr. For standard size o-rings, Ebay would have these.
GM does not sell the tube or it's o-ring. They have a pump rebuild kit. But it contains many parts and would be expensive. That is if they haven't discontinued the kit.