Can anyone tell me whether rubber gaskets need sealant? I think that most mechanics use sealant regardless of whether the gasket is paper or rubber since the sealant sort of fills any deformity. However, probably assuming there's no deformity, I've heard that rubber gaskets don't need sealant. But I also don't think paper gaskets need sealant either since paper gaskets are generally for parts in contact with coolant which like water gets absorbed into the paper thus the paper should expand. And if something absorbing liquid can't expand it won't absorb the liquid efficiently. Please advise......I'm puzzled.

Or what the f**k, I'll use sealant anyway.

 

when i built my engine for my other car, i used a marine sealant. its brown in color but never fully hardens when cured, its always somewhat plyable. i used it on almost every gasket in the engine and it hasnt leaked a drop since (been about 2 years). i cant even remember what it is called. maybe a marine mechanic here may know.