I have an 8 year old McClain trailer, tandem wheels with vault hubs. I just had to do 2 hubs with new seals, o rings and grease as they began leaking. My questions is, i want to go ahead and purge and replace the grease in the other 2, but should i tear it down and also do seals and o rings or just replace oil since the seals arent leaking. I dont want to temp fate by replacing seals when its not leaking. The general logic i see in regards to vault hubs is, if they arent leaking leave em alone.

Guess the other school of thought could be, you had 2 leaking already, how long until the other 2 start.