You can do it yourself but it sucks. Theres only a back seal, the front is the fake ass bearing buddy. I remove the grease fitting and install real Bearing Buddies, that gets rid of a lot of the grease problem.
Sticking calipers is common as is snapped brake lines, my two Epic (ameratrail) trailers have both broken the right rear brake line and lost all fluid.
I have had so much trouble with the trailer that I'm considering buying a Boatmate with oil bath bearings.
Well i just got done with the job last night and it wasn't so bad. My boy & i got er done in about 3 hrs. Bearings were in good shape and didn't have any metal filings in the grease.
Why would you want to remove the grease eark? I like the eark myself because when you grease them, it actually does get the back bearing as well. Without the eark, you never get the back one and so you have to repack & replace seals again in a couple more years.
What i found interesting though is, 3 seals were gone & 1 was still good (replaced it anyway). The one that was good was the smaller type, and the other 3 were the type with a 1/2" metal sleeve attached & were a beotch to remove. The good one popped off very easily. Why would they use 3 of one type, and 1 of another?
I replaced them all with the same as the good one.
I've had good luck with our ameritrail trailer, other than it's about time for a new paint job from all the dings. The only problem i had was when my wife was towing it and ran over a tire gater & ripped out the brake lines. So we have all new brake lines on the trailer now.