Those RockCrusher covers are nice and beefy, but can be a bit of a pain to get to seal. The bolts that they come with have a short head on them so that they wont get mangled on the rocks, but that makes it hard to keep a socket on the to get them real tight. Both my dad and my brother put theirs on and came out a few days later to see them leaking. Pulling out the socket set again for a good tighten fixed it, just hard to keep the socket on the bolt for as tight as they need to be.