[ShrimpBurrito]

Part of the confusion may be that there are 2 commonly used lubrication technologies in play here that have different roles.

One, is the EZ Lube system used in Trailmanors. Grease is pumped through a zerk fitting, goes through tubing, and then exits on the other side (and inside) the hub, where it is forced outward (towards the grease gun) through the bearings. Once you remove the grease gun, the system is no longer in play -- it simply works like a "normal" bearing/hub system. The sole purpose is to infuse grease into the bearings.

The second system is called "Bearing Buddy", and in my experience at least, commonly used on boat trailers. It works differently. Wheel bearings on any trailer get warm/hot as the trailer runs down the road. Unless the heat is excessive, that is normally not a problem, and they cool back down after the trailer stops. However, the problem with boat trailers is that, while the bearings are still warm/hot, the trailer gets backed into the water. This creates vacuum pressure in the hub, such that water can get sucked into the hub. Obviously, that's a problem, as it can/will cause the bearings and hub to rust, which ultimately will lead to untimely bearing failure.

The Bearing Buddy is an attempt to fix this problem. It is simply a cylinder that can be fitted onto the outer end of any "normal" hub, and inside is a piston with a zerk fitting on the outside, and a spring on the inside. The idea is that you pump grease through the zerk fitting until the piston floats; at this point, the spring is compressing against a pad of grease you just pumped in, thereby creating positive pressure inside the hub. This positive pressure prevents a vacuum from being created when the hot hub is backed into the water, preventing water from getting sucked in.

With Bearing Buddies at least, one can pump too much grease in, which causes the seal to blow on the inside of the hub (under the boat). This causes grease to be thrown everywhere as the trailer goes down the road (including the underside of the boat), and also thereafter negates any benefit derived from the Bearing Buddies until the seal is replaced.

Dave