Product review (5 stars): easy and inexpensive
I have a Whirlpool dishwasher, Model GU2400XTPB7, that suddenly developed a freely swinging door when I opened it.  I checked the springs on the side of the machine and though they looked intact, I replaced them.  This did not solve the problem.
Then I read about these friction pads on a repair forum and bought a pair from Amazon.  These were the solution to my problem. All I had to do to install them was to remove the bottom plate (2 screws), detach the cabinet mounting screw (1), pull the dishwasher out a few inches and slide one friction pad on each of the two bottom black door hinges.  They were tight at first, but it was an immediate improvement.  Simple, easy and inexpensive.