My water bypass gasket keeps leaking after the headjob I did. I've drained the coolant and cut out 4 gaskets and each one has been letting coolant seep out. I just added about half a gallon of coolant to the radiator and overflow tank, so it's not a BAD leak, but it's annoying me and leaving a mess on the street. So I went out and bought some high temperature silicone gasket maker. This is the stuff the previous owner had used for gasket all throughout the engine. This stuff was fine before, so it should be fine to use now.

My only problem is, Ive never made a gasket with this stuff before, and my girlfriend's (well, now future father in-law) was telling me you have to be careful how you use that stuff, and saying it's not as easy as it looks. I'm confident I can do it right, but I'd like some more advice before I drain the coolant again and make another gasket.

So aside from cleaning the surfaces really well, how should I go about making this gasket? Do I need to squirt some on both surfaces? how much should I add? Should I apply it around the hole where the coolant flows through? or just in the empty space between the hole and the edge of the water bypass valve?

 

The silicon called RTV- room temperature vulcanizing sealant.

1. Clean off and dry both mating metal surfaces with brake cleaner.
2. lay a 1/8" bead of RTV down where you want the gasket
3. place the two parts together and tighten the bolts by hand until RTV starts squeazing out from between the two surfaces
4. wait an hour, or two if its cold, then tighten the bolts either to torque spec, or one complete turn. I've bever been totally clear on this. I just tighten til it feels right for a lot of tasks as I don't have a torque wrench. Never had a leak.

The stuff is totally vulcanized (hardened to its final form) in 24hrs, but when I did my oil pan, I had the engine running in two hours briefly, then about 8 hrs after, I drove it for a while- stil no leaks.

 

thanks for the advice. i would have done it totally wrong. i would have just smeared this stuff all over the face of the part, and then torqued it down to spec, rather than bolting it down lightly and letting it sit and then torquing it down.