Water pump gasket

I just finished the timing belt/water pump project on my 2000 Tacoma (177k).
There is a water leak- looks like near the thermostat side.
I used an Aisin pump with the supplied gasket that had what I assumed was a ridge of black sealant on both sides so I didn't apply any additional sealant.
The gasket surface was meticulously cleaned and the pump was torqued to specs.
Any thoughts on this?
Looking forward to re-doing this little task...
Thanks

 

Pop it off and put a layer of black silicone on it
Also which way did you put your jiggle valve?
http://www.tacomaworld.com/forum/1st-gen-tacomas/311830-thermostat-jiggle-valve-3-4l-6-cyl-trd.html

 

In this case I did the easiest thing first, which was to remove and reseal the thermostat housing. Lucky for me, that's where it was leaking.