Yes, you can use silicone on "O" rings. Just use "sensor safe", it should say so the tube. And make sure that the surfaces you are sealing are clean and smooth. You really should test the coolant system with pressure before putting the intake manifold back on. That way if you have any problems under there you can correct then without undoing a lot of work. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "James LaLonde <deloreandmcxii@xxxx>" <deloreandmcxii@xxxx> wrote: > Yay! I'm all done replacing the waterpump and I started the car! > Yay! other than a jump start it started and ran better than ever! > Yay! it's leaking coolant like... something that leaks alot of > coolant. > > no wait... that's not a yay.... that's a boo. > > Boo! it's leaking coolant like... something that leaks alot of > coolant. > > So, stupid me, accidentally pinched an o-ring on the internal > waterpipe to the block without realizing... and reassembled the > whole dang thing. Well I got it all back disassembled... again. > > Call me a dumb@$$... > it is safe/worthwhile to put a thin stripe of RTV sealant (silicone) > around the o-ring... or some liquid gasket, to help hold the ring in > place while putting on the water-pipe, and help seal it later? Can > that stuff take the kind of temperatures I'm sure exist down in that > hell between the intake mani. and block? > > Thank you, thank you very much! > > I learned that no mater how carefully you do every step in such a > big/lengthy job.... you will F it up somewhere. > > James L 4009