Not trying to beat a dead horse here, I did search and can't find a direct answer.

My s55k started to hum last night, at idle. My assumption is pulsation dampener.

Question is, after installing a new dampener, what is the proper procedure to prime the ABC pump so it won't ingest air?

cycle through the raise and lower button a couple of time and the system will self bleed

So, install dampener, start car, cycle up and down? Simple enough.

yes

shardul, is this the same or better than having the ABC rodeo test?

Its similar to the rodeo, but not as effective at bleeding the struts in particular, as they're not exercised to the full extent of their stroke. For bleeding after an accumulator replacement, its probably fine.

Nick