KDS-18 not cleaning or draining completely

[sarabee]

Hello! I'm trying to fix a KitchenAid Hobart KDS-18 Custom dishwasher that came with the house I recently bought. I'm pretty new to appliance repair in general, but I'm trying to save this dishwasher since apparently they last forever and a new dishwasher isn't in the budget right now. It has a few issues: 1) it barely cleans residue off dishes, 2) dishes don't dry completely, 3) a small amount of water remains at the bottom, and 4) the detergent dispenser door doesn't open.

I discovered that the o-rings on the detergent dispenser were bad, so water had been leaking through and rusted the bi-metal/terminals (1st photo). I know the o-rings are easy to replace, but can I replace the plastic terminals and sand the rust off the bi-metal? Or should I buy a new part?

As for the cleaning/draining issue, I'm wondering if there's a clog somewhere in the drainage hose but I don't know how to remove the drain pump impeller/shaft pump assembly (2nd photo). A blue strip of plastic broke off very soon after I bought the house and I have no idea how it's supposed to attach to the strainer (you can see it sticking out in the 3rd photo). Sorry for the nasty state of the dishwasher. It hadn't been used regularly in several years until I moved in, and I only just discovered how gross it was when I started disassembling it.

Any advice or suggestions on how to get this thing running properly again would be greatly appreciated!

 

[cam2s]

Hello and welcome! Congratulations on your home purchase, sounds like it had fun vintage appliances in it!
Also way to get in on some DIY repair. Can be very rewarding, a great way to learn new skills, and save you some cash! A few things to keep in mind here, Hobart KitchenAids are well regarded here, but the 18 series machines are approaching 40-50 years old, so keep that in mind for aging parts that may break and parts availability in general. While there are plenty of experts here, you can purchase the 18 series service manual in the Epherma section for just a few dollars, and it will tell you everything you need to know about servicing this machine.

As far as your draining problem is concerned, just how much water is it leaving behind. No dishwasher will pump 100% of the water out, there will always be a small amount left. . I would check the drain line and the drain solenoid before taking the pump apart. You'll need to look under the dishwasher, pull the drain hose, check the solenoid for blockages, and also check (or replace) the entire drain line. Depending on how your home is plumbed, it may have an air gap, go into a disposer, or just have a t in the drain line. Check that point for blockages too.

As far as washability is concerned, the first item I would check would be if it's getting a full fill. These had a double inlet solenoid, they can get clogged up with minerals over the years or just plain fail. You'll want to start the unit, let it fill completely, then open the door to check the water level. The service manual states that a partial fill is at the top of the vertical wall of the strainer, and a full fill is 2" up the inclined plain of the strainer. It appears that you've already taken out the wash impeller, so you would be able to see if there are any problems there. Just make sure everything is seated nice and tight when you put it back together.

On the detergent dispenser, I would probably replace the O rings-make sure you have no leaks and just clean the terminals up as best you can. As long as the connect securely and can still conduct electricity that's what matters.

Hope that gives you a start, I'm sure others will hop in too with advice, keep us updated as you work on it!

 

[valvashon]

I would also check the incoming water temperature. I am in the process of installing a very similar KDI-58. It's a portable version and when I hooked it to the faucet adapter it didn't wash anything even close to clean. This was due to the low flow through my lousy faucet and the lowered water temp I had when my 9 year old was much younger. I hooked it right to the incoming line and boosted the temp up to 140 at the water heater and it did much better. My kitchen water goes through maybe 40 feet of galvanized pipe so the water that makes it to the dishwasher is now maybe 125-130 but again, it does much better so check the temperature.
Also check the little sprayer up top- it's called the "Constant Rinse" and it's easy to break off with a tall item. Post a picture of yours and I can tell you if it's still intact. An easy place to lose pressure and washing ability. A revised design is all over eBay and they are easy to replace.