First I replaced the supply hose and fittings. That was just my first assumption. I even managed to have to replace the 20 year old shutoff valve as it was leaking through the valve. Once that proved fruitless, I ran the dishwasher empty out on the floor and observed. From there I grabbed the model number, came on the website, started looking at parts. The motor to pump seal looked like a likely candidate. The list of reasons why you would want to replace the seal included leaking water. Given that there were water stains on the counterbalance and there was no visible water dripping from the motor or pump I figured this was the most likely candidate.
The actual replacement was fairly easy. The most difficult part was getting the rubber boot off. You definitely need to order at least one clamp. I replaced both to make life easier if I ever had to do it again. Working the boot off took most of the time.