First, the van: 2002 Chrysler Voyager short wheel base 3.3L, disc/drum.

It appears the brakes are dragging. Both fronts are hot to the touch after driving. Hot enough that you can't even touch the lugnuts.
Last spring I changed the pads and cleaned/greased the pins, so I think it might be an master cylinder issue.

How should I go about diagnosing this?

Thanks.