Grease fittings not releasing grease??
I just lubed the grease fittings on Jeep last week, but I noticed that the rubber things (sorry - dont know the correct name) that are behind the grease fittings just swelled up instead of letting old grease out. I took the fittings off and it looks like the grease was under pressure because 2x as much squirted out as I put in. I thought that the new grease was supposed to push out the old grease? How does it do this? Does it escape through a hole, or around the rubber seal or ??? Should I squeeze out all of the old stuff?