Coolant flange leaking after replacement
 

<center><img src="http://pictureposter.audiworld.com/86063/coolant_flange.jpg"></center><p>I replaced my coolant flange about a month ago, but it still had a slow leak. When I was bolting the flange to the head I noticed that on the left side of the flange (viewing from overhead) I could see the o-ring sticking out between the head and flange. It looked like it was not sealing properly on that side. It leaked slightly, and has grown progressively worse, to the point were I cannot drive. This weekend I took the flange off to see if I could reseat the O-ring, but it looked pretty beat up, and flat on one side.

What am I doing wrong to cause the O-ring not to seal properly? It fits in the groove just fine, but when I snug up the bolts the oring starts to bulge on one side.

put a little bit of vasoline or ky jelly (seriously) on there so it will move around
 

and not get pinched when you tighten it.

2nd. Also clean the engine surface and make sure it's smooth as can be.

Might be tightening it too much also.

try to tighten each bolt a little at a time so the pressure on the oring is even from both sides
 

if you tighten one fully the oring will bulge out the other side and when you tighten the 2nd bolt up you'll pinch and probably tear the oring

If I had to guess...
 

This is probably what I did wrong. Due to the location, and my extreme frustration at the time I more then likely tightened one side down and then moved to the other side.

Thanks for all the responses!

If the o-ring is damaged at all i would look into getting a new one
 

if it is ripped or pinched at all it will probably leak.

Still leaking
 

<center><img src="http://pictureposter.audiworld.com/86063/img_0030.t.jpg"></center><p>I took everything apart, and threw in the new o-ring that came in today (Thanks Carson!) and I buttoned everything back up using everyone's advice. The problem is that it is still leaking. The only thing I can think of is that the flange is no longer flat, it may have warped when I installed it the first time and now it won't seat properly. I will have to take everything apart this weekend when I have some time and see if the flange will fit flush against the head with nothing attached to it.

I really hate the smell of coolant!