$100 seems kind of steep to me, unless the machine is in next-to-new condition.  About a year ago a member here picked up a barely used KDS-21 for $35.  Then again, you could easily pay $500 for a brand new machine that won't last a fraction as long as that KDS-21, but will take three times as long to get the dishes done.

And I still never hear the end of it for letting that damned thing go...  :-)

BJ, it was actually Nate who I was referring to (see his lament further up).  Interestingly, he found his KDS-21 at a Habitat ReStore/SVDP complex, and as I recall that one also had an inlet valve issue, but it may have been as simple as just needing the correct fitting for the supply line. 

Steve, thanks for the comparison of the 18-20 series against the 21's & 22's.  Just based on looks alone, I prefer the 21 and 22 series Superbas over the 18-20's, particularly the Monterey models with their sleek and timeless control panels.

The WP Power- Clean Pump is a superior performer to the KD 21 and 22 Hobart designed pumps. On the KD 21s and 22s you still had to clean a messy filter and removable trap to clean by hand and all the final rinse water is exposed to this food waste, most food chunks never got to the disposer. The WP pump has a true disposer blade that grinds chunks of food, fruit pits, kernels of corn, small bits of bone, even broken glass until the particles are less than 3/16" in size and then they go through a centrifugal separator where they are removed from the water stream and held in the separation chamber and flushed away with each drain cycle. The WP PC pump also has the extra fine filter to catch tiny light things like particles of pepper. You will almost never see any food laying in the bottom of one of these DWs and when we work on the pumps on these machines there is never even a thimble full of residue of any kind left in the pump assembly.

All that said the KD 21 and 22 pump assemblies were the best pump and motor combination ever put in a KA home DW. It was  very strong and robust and fixable pump, it was Hobart's final and best effort. KA DWs were well designed and very well built machines but they were falling behind by the 1980s and they were losing money, which is why they got sold to WP. By the 80s the WP PC, KM Ultra-Wash , GE Mulit-Orbit and MT DWs were all out performing KA DWs.

KA never got rid of the messy filters, never made a DW that would heat the main wash to a guaranteed temperature, so you had to keep your water heater at 140 and if you ran low on hot water while the machine was running cleaning and drying results suffered. And by the 21 series and later they only had one final rinse, after WP bought KA we were sometimes taking out new KAs and giving the customers new WP power-Clean machines to dissatisfied customers because the KAs did not clean or dry as well as the WPs did.

I do love KA DWs over DW history they are one of the most significant DW builders. I have three KA DWs in my two homes, but I like to be honest about what these great machines can and cannot do.

I recently got a KDSC-18 for a friend of mine for 30$. It's in relatively good shape but he doesn't like it that much. He mostly wanted something inexpensive to fill the dishwasher spot in the cabinets in his new house as the even older Inglis Royal that was left in the garage was looking bad... The racks in the Kitchen Aid aren't that bad but could be better and one of the detergent dispensers has a small leak.

Well, I don't think he wants to get rid of it! He just doesn't like it as much as others do... And he got it because it was inexpensive!