Ok, i left that goofy little rubber seal off of my water pump. How important can this little thing be? Yes, that is right, I am that lazy.

here is a picture of it on the old water pump.

 

Nevermind. I broke down and installed it. But I would still like to know how important it really is.

 

i dont think it is that important as long as no water leaks out. i beleive that piece is used to support the timing cover. since the covers are held in by bolts i dont think it will effect any thing. just to be on the safe side double check everything and no wobbly parts. but i honestly do not think it is of importance. i changed many timing belts at work and never really noticed that part until now

 

many little rubber parts are there only for the vibration !!

as long as no wather leak, no probs!!!
see ya soon