VOLVO, seized riser bolts

[pine island fred]

Got a call today, friend noticed evidence of water leaking from the manifold/ riser point on his 2 yr. old glastron. Is a 350 duo-prop, closed cooling system. This morning he started replacing the gaskets and snapped off one bolt, managed to get 5 out and 2 wont budge. Got my torch, drill, easy-outs together and plan to help him tomarrow. Can anyone give me a heads up on something that might not be to obvious when I tackle this.
While here, a question. Does have a closed cooling system. I suspect that the manifold is raw water cooled. If so, could the salt water work its way up the bolt holes in the manifold to the bolt treads? Any recommendations on what to put on the threads to prevent a reoccurance? Anti -sieze normally contains copper or nickel or molidibium, all metals. With the salt, is this a good idea? Might sound old fashion but my can of wheel bearing grease has served me well since 1961 in all applications. How about silicon sealer on the threads? Thanks for your input. FRED

 

[Don S]

Re: VOLVO, seized riser bolts

I suspect that the manifold is raw water cooled. If so, could the salt water work its way up the bolt holes in the manifold to the bolt treads?

Yes the manifolds are raw water cooled, but they are blind holes and should not see any salt water. Of course of the gasket is leaking it could leak onto the threads too.
I wouldn't use silycone, but some Merc Perfect seal or Prematex Aviation 3D gasket sealer works great on threads like that. But DO NOT use it on the new metal shim gaskets Volvo is using on the newer engines. Follow the OEM instructions exactly, come with the gaskets.

http://www.permatex.com/products/au...tex_Aviation_Form-A-Gasket_No_3_Sealant_a.htm

 

[pine island fred]

Re: VOLVO, seized riser bolts

Thanks for the head up. FRED