Posted by Gordon Maney on Friday, November 04, 2005 at 7:47AM :
In Reply to: head gasket leak - any luck with liquid sealer posted by Garrett Mayer on Thursday, November 03, 2005 at 10:02AM :
I struggle to know if you are linking the two together.
It is common practice by many to use suitable, spray sealer on head gaskets. Those sealers are used to reduce any possibility of compression leak at the head gasket. If your head AND BLOCK surfaces are flat and true, you really don't need it, but I admit to using it as a next level of certainty. I emphasize the block surface because too many think only about the head. Cylinder blocks are resurfaced, just as cylinder heads are resurfaced, and for the same reason. An inline block is a less rigid casting and more prone to changing shape than a V block, so you need to be thinking about that at the time of any out of chassis, major engine work. Sealer is not the way to compensate for distorted castings.
If your surfaces are flat and true, your gasket is new and your torque spec and sequence is right, you won't leak. Subsequent torque checks are good, also, after some initial period of operation.
If you have water leaking by a head gasket somewhere, you are not going to fix that with a pour-in-the-radiator stop-leak product, and if you do, it is likely a precarious fix.