to silicone or not to silicone,

[hilsideser]

...that is the question. I am about three rusty bolts from putting the pump housing back on the front of the cylinder head and before I do it, I want to ask you gurus if silicone is a good idea or not on the gasket faces.

 

[Guest]

I hate silicon. I prefer Permatex Aviation Sealant. I assume you are talking about the water pump housing, and not the head gasket. Definitely nothing on the head gasket.

 

[DougF]

Everyone has their preferences. If silicone is the only option over a nontreated gasket, use silicone. There are products on the market that many of us prefer over silicone.
My preference is Permatex The Right Stuff.

 

[Brosky]

Either Bill or Doug's solution works for me, but I'm older, so I tend to lean to the Aviation Sealant.

And I don't necessarily mean that Bill is as old as me...

 

[TR3driver]

I also grew up using Permatex #3 ("Aviation Form-A-Gasket" except back then it was just called "Permatex" since everyone knew what that was). But today I much prefer Hylomar.

Silicone would be a last resort IMO, and then a VERY thin layer, not even enough to cover the gasket surface.

 

[Geo Hahn]

I, too, like the Hylomar in this and many other locations just because I expect to be back in there... perhaps on a dark and rainy night in a motel parking lot. Hylomar never sets up and releases with ease.

 

[MTribe]

Anyone know if "Wellseal" sold by Moss is roughly the same thing as Hylomar?

 

[Geo Hahn]

It is not... though Moss sells Hylomar.

I have never used WellSeal but from the applications where it is mentioned it may be closer to Permatex Aviation Form-A-Gasket mentioned above.

 

[TR3driver]

Only resemblance is, it's pasty stuff in a tube. Different base ... almost more like Permatex #3 but in a tube. Nearly the same color as Permatex, too.

According to
https://www.cromwell.co.uk/static/healthandsafety/coshh/stag wellseal.pdf
it has a petroleum base in perchloroethylene solvent (same stuff they dry clean clothes with).

I believe Hylomar is a polyurethane base, not sure what the solvent is. Acetone, maybe ?

 

[RonMacPherson]

MB went through three different sealants on the front cover seals of their dohc 6 cylinder engine in the 00's. They could not get a sealant or sealing procedure that would last more than about 45K miles. UNTIL they discovered The Right Stuff,

course MB took a Toyota concoction and put it in MB packaging,until someone discovered when MB was on national backorder that it was The Right Stuff.

IT WORKS! It seals and can be driven off almost immediately. minimal setup time is needed.

 

[tdskip]

Down here in SoCal most of the local population does use silicone.

But that might be the answer to a slightly different question that the one you asked...

 

[Mickey Richaud]

Down here in SoCal most of the local population does use silicone.

But that might be the answer to a slightly different question that the one you asked...

It was only a matter of time...