I used a burr to flare the hole a bit, but, just on the top edge. Oring inserts nicely, and doesn't get trashed on installation.

 

i was doing doing my timing chain gasket and changed my water pump and heard of others having issues so i whent to autozone and they had this two dollar box of O-rings there was 16 O-rings some the same sizes but a wide range of sizes i put two on mine than hit it up with some RTV as well

 

I replaced my waterpump recently and I deburred the edge of the hole first then a light coating of petroleum jelly and installed the tube and O ring. Then, to be sure, I cleaned the area and put a light coating of high temp. RTV. Just hope I never have to replace it again.

 

just took the truck for a spin to burp the cooling system and i have no leaks.looks like the old silicone on the 0 ring trick did the job.thanks guys.

 

Glad it worked. Doesn't it just grind when a simple thing causes so much trouble. Makes me pull my thinning hari...lol

 

you got that right gdstock.done the same job before with no hassles then this happens.damn thing gave me 40 fits,then i thought i had a major problem.water pump made some nasty groans till i got the air purged out of it.