There should be some kind of washer on the drain plug. Some people use rubber, some use copper, some use fiber. It goes between the bolt head and the pan and it crushes just enough to provide a good seal. I've found the rubber washers can get old and squishy and don't always provide enough of a seal to prevent leakage.

Myself, I'm a fan of the copper washers. I just replaced my drain plug with a Fumoto oil drain valve, however, so I don't use a drain plug any more.

 

i think were referring to the same thing lol..i call it the seal or gasket but its basically a rubber washer. i just looked up the fumoto. didnt know they had something like that its sick. does it just screw in like the bolt would? and any problems with leaking with it?

 

I installed my Fumoto drain valve in July. No leak problems since. It makes the oil change super fast and easy. I don't need a ratchet and socket to do an oil change. I also don't need to jack up the truck. One quick flick of the wrist and the oil is draining. Another quick flick and it's done.

If you do get a Fumoto make sure you get the oil drain adapter for the 4.3 Vortec. The way the cast aluminum pan is on these engines you'll need the adapter because the valve won't sit flush against the pan.