Rtv

[Jakey]

Straight from the manufacturer:
http://www.permatex.com/products/aut...ket_makers.htm

In areas under high oil pressure, red RTV will leak. I'd used both red and black RTV on a variety of hydromechanical transmission assemblies and the black always holds better. For reference, I believe our relief is set as 3000 psi on our hydrostatic unit.

[tim]

For anything engine related I use Permatex UltraBlack and never had problems. I absolutely hate any blue RTV and have never had a reason to use red so I cant say anything about it.Ultra Black for the win.