Relating to my other post of a blown rear engine seal,
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=73745, elephant hose mod routing is very important. The way I had my EHM routed is shown below, (blue line) has a low spot between the wheel and where it vents to atmosphere. In this low spot water vapor condensed to water, then froze to ice, plugging my hose. When I started my jeep to drive the pressure generated by the blow-by could not exit out the EHM but instead found its way out my rear main seal.
Moral of the Story: Be sure that everything that gets into your EHM can drain out.
