Inspect brakes...how do the shops do it?

I am in the process of repacking the bearings on my 5th wheel along w/ checking the brakes and was wondering how the rv shops check the brakes when I take it in for inspection. As far as I can see the only way is to take the hub off which I don't think they do nor would I want them to due to then possibly getting dirt in to the outer or inner bearings. Just curious.