Discharge Pump Housing

First off, I must give thanks to Partselect.com for excellent service. They had the parts I needed, a Diagram of how the parts should go into the Dishwasher, and shipping was very quick and reasonable priced. Thank you Partselect.com.


After dinner we heard our Maytag MDB5100AWW dishwasher start grinding during its wash cycle. Needless to say we found this quite concerning, as this is not what a healthy dishwasher should sound like. After fiddling around with it, I started researching the issue and found Partselect.com where it was stated the “Discharge Housing Assembly (Discharge Pump Housing)” was a common failure point. After disassembling the “Pump and Motor” section of the dishwasher, it was confirmed that the Discharge Housing was indeed broken. Since this Dishwasher is over 8 years old, I figured that I might as well replace a few other parts as well, since I'm in there working on it.


Following the blow-up image of the Pump and Motor picture;

Unscrew part 34

Pull out part 1

Lift Part 2, which is attached to part 36

Unscrew part 5 (6 of them) from part 4, be careful not to loose part 3, sitting inside part 4

Lift out part 6 and 7

Unscrew part 8 and lift out part 9

Unscrew part 27 (three of them) and lift out part 11

The bottom plate of this part is the broken part.


Now, since we are in here replacing a part, we might as well replace a few other parts and give this dishwasher a little longer life. I opted to replace the following parts as well, being that my dishwasher was over 8 years old and the gaskets were showing some age.

Part 4 – Pump Cover and Secondary Filter Assembly; I replaced this part because food often gets caught inside the filters and will throw off the balance during a wash or rinse, thus putting premature wear on bearings and o-rings. My filter had a bunch of food on one side, and the only way to remove the food was to slit open a section of the filter, thus damaging the filter screen.

Part 37 – O-Ring that goes inside the Pump Cover and Secondary Filter Assembly. O-rings are rubber and do wear with age. My dishwasher didn't even have this o-ring; now it does.

Part 3 – Lower Spray Arm Seal; I noticed when pulling these parts out that the hard water in our living area was making these somewhat brittle. When ordering these, get two of them, as the picture indicates. If you order one, the package only contains one, and not two was the image shows it should have.

Part 11 – Discharge Housing Assembly (Discharge Pump Housing). This is the part that is making all the grinding noise. The new part will show that it is built a little differently. It appears that Maytag figured out the weak design of this part and made the replacements stronger.

Part 17 – Even though I ordered this, you don't need to order this part if you order the Part 10 kit. The part 10 kit will include this o-ring. Because its an O-ring, I replaced it; as stated above, o-rings do breakdown.

Part 25 – Pump Gasket; This part should really be called the Pump Housing Gasket, as it isolates the Pump Housing bucket and the Dishwasher tub. I bought this because my original gasket was looking pretty nasty and was coming apart.

Part 10 – Seal Kit (Motor/Pump) (Motor/Pump Impeller and Seal Assembly), this kit includes several components that if purchased separately would easily be twice the cost of this kit. Again, seals and Motor Pump seals are a good thing to replace when needing to do work inside the dishwasher.


Continuing on from the previous dis-assembly list;

Unscrew part 12 and remove part 14, 15 and 16.

Unroll part 17 (o-ring) and remove part 18.

Unscrew parts 19 and carefully remove part 20, being VERY careful to not loose part 39.

Lift out part 22, which will include the bearing inside of part 22.

Pry out part 24 with a pick (the replacement is in the kit of part 10).

To remove part 25, you must Remove part 12 of the Door Assembly (see the Door image) to reach the motor element.

Next unscrew part 14 of the “TUB” i

Figure out how to remove the spray arm (15 min); remove all the parts below (15 min); figure out what's not right (5 min). the pump discharge head is two parts. The flat disk that is attached to the under side of the discharge head came off and was being ground up by the impeller nut. Hence the noise. I superglued it back together and ordered the replacement parts. the superglue lasted through about 1 rinse cycle. The repair parts arrived the following day, and since I already knew how to disassemble and reassemble, the actual replacement was about 15 minutes. The dishwasher hasn't been this quiet in over 2 years.

I removed the plastic retainer that held the lower spray arm in place. After removing the lower spray arm I was able to remove the 6 hex screws that held the cover over the filter screen and the discharge housing assembly. I was then able to remove the bolts that held the upper part of the discharge housing assembly, and replaced it with the new part that I received. The rest of the job was simply putting it back together.

Note: While repairing the broken part, I noticed a small leak under the machine around the float assembly. This was simple to fix. Remove the small lock ring on the bottom of the float. Pull the float out and clean the grease and soap scum out of it. Put it back in and attach the lock ring. No more leak and the water gets turned off when the float activates the switch. Something that everyone should check periodically.

Using the part list (on your web site)as a guide to remove the parts,Part 32 remove by hand turning counter clockwise,remove screws #5,remove parts(33,34,31,2).
Remove #36 remove 4,3,,6,7,,8,9,remove screws#27 then remove #11 which has a plate part of it but broke on the underside (you can't see it in the picture)it will rub on the fins of part#14 during the cycle when dishes are being washed creating a grinding noise.
i Do suggest to replace the seals,38,37,you may coat the new seals with liquid hand soap for easier installation.

I first removed the washer arm. Be careful because it is screwed on with the large center plastic piece with right hand thread. That allowed me to take the arm and disc off.

Next I took 6 screws loose with the allen wrench. This allowed me to get to the filter ring. I removed it and that allowed me to get to the three screws holding the discharge. I used a 5/16th socket to remove them.

A plastic disc that was part of the upper pump came loose and caused the noise. I replaced the upper discharge housing (with upper pump as part of it) and upper discharge housing gasket and reversed the order to reassemble.

The exploded diagram was a terrific help

Remove bottom rack. Unscrew the retaining ring on the wash arm, remove along with wash nozzle. Unscrew the eight retaining screws on the filter cover and remove (be carefull not to lose the two plastic bushings). Pick off and set aside the wash fan. Remove the six retaining bolts on the discharge housing. Pull up and remove the discharge housing. Remove the gasket (buy a new one, cheap and easier) with small screwdriver. Push gasket into new assembly. Under plastic nut with pliers and take off the plastic bushing that the wash arm rides on. Install new housing assembly with the parts that was taken off in the reverse order. Be carfull when installing the filter cover to make sure the drain outlet is aligned or mated to drain. Gently push down until the filter in down and continue reassembly.


(PS: Never use Sears parts, they extrembly slow as well unable to deliver on time).
Wash your dishes

I took apart the lower spray arm apart and removed the 6 hex screws. I noticed that the little plastic circle thing had been ripped off the dome-shaped thing. I replaced the part and put it all back together.

Initially I suspected something had found its way to the impeller or the macerator, began to disassemble top down. Upon removal of the discharge it was apparent the plastic disc at the top of the discharge was sheared off. Located the schematic at PartSelect and ordered the discharge. Received part within 3 business days and installed new discharge in about 30 minutes. Required 5/16 socket and hex head driver. Recommend ordering new gasket with part.

Other parts used:
Lower Spray Arm (#2)
Upper Spray Arm (#33)
Snap Spray Retainer (#31)

Removed upper and lower washing baskets.

Pulled off Upper Spray Arm (#33). It pulls off easily by hand. No tools required. Replaced with new Upper Spray Arm (#33) and Snap Spray Retainer (#31).

Removed Large Spray Arm Cap(#34,)which has a right hand thread. This allowed me to take the Lower Spray Arm(#2)off.
Removed Filter Guard (#36).

Next I removed the 6 screws from the Pump Cover & Secondary Filter Assembly (#4) with a Torx screwdriver. Removed Lower Spray Arm Seal(#3), Pump House Filter (#6)(which I cleaned), Assembly, Rinse Arm (#7) Jump Up Nozzle (#1). Unscrewed Discharge Housing Nut(#8) by hand. Removed Support, Wash Arm (#9). This allowed me to remove the three screws holding the Discharge Housing Assembly(#11)with a 5/16th nut driver. Next I removed the Impeller Screw (#12) with a 5/16th nut driver. You must hold the Impeller Assembly (#14) firmly while loosening the nut. Removed Impeller Assembly (#12) and Plate, Suction (#15). Cleaned out area of debris,lint, etc. Put back old Plate, Suction (#15) and replaced Impeller Assembly (#14) with new part. Replaced Upper Housing Gasket and Discharge Housing Assembly with new parts. Put back all parts in the reverse order I removed them replacing the O-Ring (#37) with a new part. This O-Ring goes in the Pump Cover & Secondary Filter Assembly (#4).

After completely assembled it ran as good as new!

unscrew screen and cover and unbolt impeller replace with new parts. everything goes back together easily, anyone with even minimal repair skills should be able to do this repair.

Located circuit breaker for dishwasher and turned off breaker to secure power going to unit. Removed water spray bar arm inside dishwasher basin by unscrewing center nut and unclipping tabs against arm. Removed sheet metal access panels on bottom front of unit. Removed two individual plug in wires to temperature thermister. Removed 4 conductor plug wiring going to motor. Removed ground wire going to motor frame. Located plastic handle which cam locks motor / pump assembly into place. Pulled handle down gently to unlock from detent and turned clockwise to release pressure on assembly. Removed motor / pump assembly from dishwasher enclosure. Installed all new parts purchased as listed above utilizing parts breakdown aquired from PartSelect.com. Reinstalled motor / pump assembly in reverse order as listed above. Tested and ran unit with no problems. Thank You PartSelect.com, Robert.

From the inside I removed all of the accesories down to the impeller . I replaced the impeller as a precaution measure just incase any wear from the backing plate of the dischareg housing coming undone. and reassembled the unit. It is very easy if you have a repair manuel. I received my parts the next day. Great company

i removed the strainer cover and then removed the discharge assembly. then repeated steps to finish.. parts select was very fast and cheap ordered ontuesday and arrived on thursday. I will recomend parts select to all

removed the agitator,and a couple of baskets til i was able to gain access to the pump impeller & pump housing. i replace those parts,put back together,all works great now

Removed all parts down to wash impeller following online videos and parts breakdowns (took a while to figure out how to do this). The only difficult part was separating the Discharge Pump housing from the Suction Plate. They are fitted together with friction, and a flat-blade screwdriver can push them apart. Replaced broken parts including Wash Impeller, Suction Plate, and Discharge Pump Housing. Purchased Filter Support because it was involved and appeared to have been damaged, but the new part looks identical to the old part. Purchased new o-ring & gasket to avoid digging them out of broken parts. Cleaned out the spray arms top & bottom and it now works like new!