Newbie needs help with KDS-18 not cleaning dishes

[65buggydude]

My girlfriend and I recently bought a house built in 1977. It has a KDS-18 dishwasher built-in. I'll save you all the details, but let's just say the PO of the house didn't exactly take care of things at all! Anyway, I'll get right to the my point- I've done a lot of troublshooting of this machine and here's what I know to be true:
1. The drain hose was full of gunk so the machine couldn't drain completely. I replaced the entire drain hose with new. I also replaced the air gap because the old one was broken. The machine now drains all the water out with some extra time to spare.
2. The detergent cups would not open reliably. I took them apart, cleaned off the crud, replaced the shaft seals, reinstalled them and slightly bent the bi-metals. Both cups open like a dream every time now!
3. The machine drain valve works as it should - no gunk in it and snaps open and shut with a solid 'click'
4. The water level is right where it should be. During the pre-wash, wash and rinse cycles, the little blue rod from the overflow preventer dances ever so slightly occasionally on the microswitch lever. I also added 2 quarts of water once during a wash cycle. It made no noticeable improvement to the cleanliness of the dishes.
5. The water temperature is I believe correct. When I open the machine door duing the wash cycle the steam rolls out of the machine! The wash water is much hotter than what comes from the kitchen faucet!
6. I've followed the troubleshooting things from the manual I downloaded off this site - I've cleaned both the fine mesh filter and the plastic filter located at the bottom of the pump housing inside the tub.
7. All wash arms turn easliy by hand. The small plastic wash arm (I cannot recall the proper term) located on the "ceiling" of the tub is there and turns freely. Both wash arms are clean and free of gunk inside them.
8. It doesn't seem to matter if dishes are on the upper rack or lower rack. I find dirty dishes in both places.
9. I pre-rinse all of my dishes and I have tried 3 different detergents.
10. I pulled the pump impeller out to check for cracks / broken edges. It looks good to me.
Here's what I don't know how to test:
Lower wash arm RPM
Upper rack wash arm PRM
Is there a way to test the pump pressure?
Is there a way to see what's happening inside without making a huge mess in my kitchen?
Thanks in advance. My GF is ready to $#!t can this machine but I think it can be saved!

 

[whirlykenmore78]

Sounds like a spray system problem:

It is not uncommon for the bakelite hub of the lower wash arm to go out of round which will cause water to spray back into the wash tank instead of up through the arms. This reduces pressure to both arms and can cause the lower arm to stall instead of turning.

If the problem is mostly in the upper rack make sure that the tube that feeds water to the upper wash arm is not wore out/cracked and nothing is caught in the China Guard under the arm and it is not broke. If either is the case it will stop the upper arm from working.
WK78

 

[revvinkevin]

Mike it sounds like you’ve been very thorough thus far!

This may be a silly question, but when the dishwasher is operating during wash or rinse, can you hear the water forcefully splashing around inside?

Regarding “is there a way to see what’s happening inside...”... do you know anyone who owns a GoPro video camera who will allow you to borrow it? Put it inside with the waterproof enclosure, then some sort of flash light in a ziplock bag and vòila!

Otherwise a much more labor intensive way would be to custom fit a plexiglass panel to the door opening, then secure it with clamps, etc.

I’m sorry I’m not able to offer any other suggestions or advise.

 

[tomturbomatic]

Congratulations.

The wash arm support might be worn. You should not have to rinse by hand with an 18.

 

[chachp]

The forbidden view......

<span style="font-family: helvetica;"> </span>

<span style="font-family: helvetica;">Get a clear plastic shower curtain and some good clear packing tape.  Cut the shower curtain to the shape of the opening and tape it in.  You've got a clear view into what's going on.  This is my 21 series machine but I think your's should look about the same when its running.  In this machine I had a bad wash arm support and the arms were barely turning it also had a bad filter screen but the design is different from yours so that wouldn't be an issue in this machine.</span>

<span style="font-family: helvetica;"> </span>

<span style="font-family: helvetica;">I would start here, see how it's moving water and go from there.</span>

<span style="font-family: helvetica;"> </span>

<span style="font-family: helvetica;"></span>

 

[combo52]

KA KDS-18 Cleaning Problems

Hi Mike, It sounds like you checked out most possible mechanical problems pretty well which leaves the chemical problems.

 

How hard is your water ?

 

Exactly which detergents are you using and how much ?

 

Exactly what is not coming off the dishes etc ?

 

Do note, US home DWs are designed for dirty dishes and in many cases rinsing most soil off dishes can sometimes leave a worse final result, sugars soften water, oils help activate detergents and reduce foaming, acids reduce spotting and mineral deposits etc.

 

And also note some items just don't wash well in any DW and will not look clean, replace these items if possible.

 

25 years ago we bought new SS table wear and it looked terrible after coming out of the DW, so I returned it, We bought a 2nd set and it did not fare much better so I took it to the mountain house where it seemed to wash much better in the softer water there.

 

We bought a third set that worked great from day one and still cleans beautifully and shines coming out of our 1987 WP DWs to this day.

 

John L.

 

[65buggydude]

WK78, Thank you for the input! I checked the China Guard. It is not broken. The Bakelite hub does have a groove in it. I don't know if it is supposed to. I'm not sure what it should look like.
I also know the lower wash arm does "wiggle" a bit when I grab the end of an arm and move it with light pressure "up and down." I can see a tiny bit of play in between the lower wash arm bushing and the wash arm support shaft. I'd say the end of the wash arm is able to move up and down about 3/8" to 1/2". I'd be willing to bet I'm losing some pressure through the Bakelite hub after 40 years of service.

 

[whirlykenmore78]

It is very likely you are losing pressure at the lower WA:

Listen as the machine is filling and if you hear a clunking sound as the pump catches prime that is a worn out Lower wash arm popping up and hitting the lower rack. This is how I figured out that my Mom's KDP-20 needed a new arm.

Another way to check is to stop the machine and restart it full of water. You should hear the motor start and a whoosh of water through the arms. If you hear a clunk and or no whoosh, bad wash arm. In either case you are losing pressure and the arm is not turning.

Post pictures of the (Groove in the hub) and the WA support so we can see if they are wore out. If so I know someone here will have the parts you need.
WK78

 

[65buggydude]

revvinkevin, thank you for your input. I can hear the water splashing around inside. It just doesn't sound as "fast" as my 2002-Vintage GE Profile I had at my previous home. With regard to the GoPro, I'll ask around. I think a co-worker might have one with a weatherproof case.
I did consider using a clear dollar store shower curtain and some duct tape so I could see inside. I just haven't gotten that brave!

 

[qsd-dan]

Carefully inspect the upper supply manifold tube (Part# WP4171544) that connects to the upper washarm. If it fits loosely at either end or has rips/tears/holes, you'll lose pressure there.

https://www.ebay.com/itm/WP4171544-...396617&hash=item596d030fcc:g:0OgAAOSw-L9gbGKd

There's also a bellows seal specific to the 18 series only that seals between the upper rack and the manifold which is known to tear after decades of use. The Hobart part# is D-116028, I have no idea what the updated Whirlpool part# is. That part has been discontinued for many years now and virtually impossible to find but Combo52/John Lefever has mentioned in the past that he has a few of these available in stock.

The upper washarm could be worn, its common for these to wear out after several decades of use. They have been discontinued for over a decade but still pop up on Ebay.

Pardon Our Interruption...

 

[65buggydude]

combo52:

Our water was a bit hard. We had a water softener installed 2 weeks ago. More on that in a moment. To answer your questions about my pre-rinsing of the dishes, take a typical morning breakfast as an example: If I made scrambled eggs, pancakes, and bacon we woud load those dishes in the dishwasher. There would be some maple syrup residue on each plate, a few pancake crumbs and egg bits. Nothing larger than a pencil eraser and no more than a couple of tablespoons in total. We don't leave what I would call large amounts of food on dishes. Then later that day we'd have lunch that may be grilled cheese sandwiches, a vegetable and some kind of fruit. The lunch plates would have no visible bits; but may have some buter residue from the sandwiches. By the way, we are a family of 3; so there aren't many dishes generated at a meal. I'd put the grilled cheese skillet in the machine along with glasses and stainless steel silverware. We tried Norwex detergent in the pre-wash and wash cups as the manufacturer recommends. When done, about 20% of the dishes would have some scrambled egg bits, and some unidentifiable residue on about 40% of them.
Every load we tried had similar results.
Fast forward to now. We now have a water softener. The water feels great. showers rinse better, hand washing dishes uses a tiny bit less soap. This past weekend, I gave the old KDS-18 another chance. I'm happy to report that out of a load, we only had 2 dishes with anything wrong: a coffee cup with some gunk left inside and a glass with some broccoli that re-deposited from a dinner plate.
I'll run a few more loads, but it seems the softer water is helping the machine clean more thoroughly. I'still think that lower wash arm has some wear on it.

 

[awooff]

Soft water

Good Soft water to the dishwasher is under preached! Recently changed from regular pellets to rust remover salt pellets which made a huge difference with my softner and dishwasher - im now using 1/4 amount of dish detergent and have suds leftover at the drain of my shower.

 

[swestoyz]

You are going through similar motions to what I went through with a KDS-20.

Once I resolved the hard water problem and installed a softener properly set-up for the amount of hardness coming into the house (chemical issues - check), and replaced the main wash arm support AND a new wash arm (major mechanical issues - check) - it washes like a dream. There should be NO play with the main wash arm.

A good, quality detergent should also not be overlooked (anything eco branded or sold through a MLM company probably won't make the cut in your Hobart). I was using some cheap but phosphated detergent during the wash cycle with mixed results, paired with an enzyme packet for the pre-wash cycles for either the Heavy or Pots and Pans cycles. Once the cheap stuff was gone I switched to a Cascade commercial powder (they call it "Professional") with actual sodium carbonate for the main wash (non enzyme and no phosphates) and it was washing like new again. Everything felt clean and not chalky and I rarely find a dish with anything left behind, save for maybe a gunky fork every so often.

It is getting harder and harder to find a non enzyme powdered dishwasher detergent, but keep an eye out and you'll eventually find one. Some here swear by Cascade Fryer Boil Out but I feel that's overkill when I get can the same results for less $ and no phosphates.

https://www.amazon.com/Cascade-5953...dchild=1&keywords=59535&qid=1618971096&sr=8-2

Ben

 

[stevet]

Agreed and agreed!

I agree with Ben about making sure that the wash arm support and wash arm are in good condition. A large volume of water can escape from under a worn support as there are actually 2 seals to prevent that from happening. That is more critical than a worn arm itself. A worn bushing in the center of the wash arm will cause the arm to wobble while it rotates and can slow it down but the full pressure from the pump itself dictates how well both wash arms work to clean your dishes.

So make sure the feed tube under the top rack is good and the parts down below are good and go from there.

As far as what Aaron mentioned about the softener, when a softener is set up, you need to know how hard the water is in grains per gallon (gpg) as well as how much iron is present in your water. The level of iron gets added to the gpg of the water which now becomes what is know as the compensated level of hardness. The iron reduces the effectiveness of the softening media.

This level will determine how often the softener has to regenerate. Iron coats the softening media and renders it less effective. Aaron, that is why changing to the pellets that are made to help remove the iron deposits has resulted in your softener working better. Those pellets stirp away the iron deposits on the media and return the media to full effectiveness.