Air Shock Question

[superduty]

Hi All,
I stopped by a local H-D dealer today and picked up a small hand pump to add some air to my shocks. The insisted on collecting my name/address info so they can send me info on upcoming events, however they seemed a bit less enthusiastic when they asked the year, make, model of my bike and I told them. :)

Anyway, so I have a pump and want to experiment with some adjustments when Mrs. SuperDuty rides with me. I have a jack, but no adapter yet, so I don't think I can get the rear wheel off the ground. Is that absolutely necessary when adding/checking air pressure?

Thanks.