Whirlpool WDT750SAKZ – Spray arm not rotating Repair Guide

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Model: Whirlpool WDT750SAKZ
Brand: Whirlpool
Model Number: WDT750SAKZ

🔍 Problem Description

Remove spray arms; clear holes; check water pressure and pump

📋 What You’ll Need

  • Spray arms
  • Circulation pump

    • 🔧 Step-by-Step Repair Instructions

      🔧 Step 1: Remove spray arms from dishwasher

      1. Open the dishwasher door completely until it rests horizontally.
      2. Remove the lower dish rack by pulling it straight out toward you on its rails until it clears the dishwasher cavity.
      3. Locate the lower spray arm at the center bottom of the dishwasher tub, directly above the filter assembly.
      4. Grip the lower spray arm hub (the center cylindrical piece, approximately 2 inches in diameter) with your dominant hand.
      5. Rotate the spray arm counterclockwise one-quarter turn (90 degrees) while applying slight downward pressure.
      6. Pull the spray arm straight up and away from the mounting hub—it will lift off completely with no tools required.
      7. Look at the underside of the upper dish rack—the middle spray arm is attached to the bottom center of this rack.
      8. Locate the gray or white plastic retaining nut at the center of the middle spray arm (approximately 1.5 inches in diameter).
      9. Using your fingers, rotate this retaining nut counterclockwise until it threads off completely—typically 6-8 full rotations.
      10. Pull the middle spray arm straight down and away from the mounting post on the rack.
      11. Pull the upper dish rack out approximately 12 inches from the dishwasher cavity to access the top spray arm.
      12. Locate the upper spray arm mounted to the top of the upper rack, centered along the back edge.
      13. Identify the single retaining clip—a small plastic tab positioned on the right side of the spray arm mount.
      14. Push the retaining clip toward the left while simultaneously pulling the spray arm downward.
      15. The upper spray arm will release and drop free from its mounting bracket.

      🛠️ Step 2: Clear all spray arm holes

      1. Grasp the lower spray arm hub in the center of the dishwasher floor and pull straight up with 5-10 pounds of force until it lifts free from the mount.
      2. Hold the spray arm under bright light and locate all spray holes – you’ll find 16 holes total: 8 on the top surface and 8 on the underside of each arm.
      3. Fill a bowl with 2 cups of white vinegar and submerge the spray arm for 10 minutes to dissolve mineral deposits.
      4. Take a wooden toothpick or straightened paper clip and insert it into each of the 16 holes, pushing through any debris until the toothpick passes completely through the hole.
      5. Hold the spray arm under running tap water and visually confirm water streams freely from each hole in a steady stream.
      6. Open the dishwasher door and locate the middle spray arm mounted on the underside of the upper rack.
      7. Turn the spray arm hub counterclockwise 90 degrees and pull down to release it from the water supply tube.
      8. Count 12 spray holes on this arm – 6 on top and 6 underneath.
      9. Repeat the vinegar soak process from step 3, then clear each of the 12 holes with a toothpick.
      10. Run water through the arm to verify all holes spray freely.
      11. Remove the upper rack completely by pulling it forward until it stops, then lifting up on both sides to clear the track rails.
      12. Locate the small white spray manifold at the top rear of the dishwasher tub.
      13. Twist the manifold cap counterclockwise 1/4 turn and pull the entire assembly down.
      14. Identify 8 spray holes in this component.
      15. Soak in vinegar for 10 minutes, then clear all 8 holes with a toothpick and verify water flow.
      16. Reinstall by pushing up and turning clockwise 1/4 turn until it stops with resistance.

      ⚙️ Step 3: Check water pressure to dishwasher

      1. Turn off the dishwasher circuit breaker at your electrical panel.
      2. Locate the water supply valve under your sink, typically on the right side near the back wall where the dishwasher connects.
      3. Turn the water supply valve clockwise to close it completely.
      4. Place a bucket or shallow pan under the water supply connection point beneath the dishwasher.
      5. Use an adjustable wrench to loosen the braided stainless steel supply line where it connects to the 90-degree elbow fitting at the front left corner of the dishwasher base (approximately 3 inches from the left edge).
      6. Completely disconnect the supply line and let any remaining water drain into your bucket.
      7. Attach a water pressure gauge (0-200 PSI range) to the threaded end of the disconnected supply line using thread seal tape wrapped 3-4 times clockwise around the threads.
      8. Turn the water supply valve counterclockwise to fully open position.
      9. Read the pressure gauge. Acceptable water pressure for the WDT750SAKZ is 20-120 PSI, with optimal performance at 40-60 PSI.
      10. If pressure reads below 20 PSI, check the supply valve under the sink to verify it opens fully, then check your home’s main water pressure regulator (typically located where the main water line enters your house).
      11. If pressure exceeds 120 PSI, install a pressure-reducing valve on the dishwasher supply line rated to reduce pressure to 50-60 PSI.
      12. Turn off the water supply valve clockwise.
      13. Remove the pressure gauge and reconnect the supply line to the dishwasher’s 90-degree elbow, tightening hand-tight plus one-quarter turn with the adjustable wrench.
      14. Turn the water supply valve counterclockwise to reopen.
      15. Inspect the connection for leaks while water flows for 30 seconds.

      🔩 Step 4: Inspect circulation pump operation

      1. Locate the circulation pump mounted on the left side of the sump assembly, approximately 4 inches from the bottom of the dishwasher tub.
      2. Identify the gray 2-wire connector attached to the circulation pump motor, positioned at the 2 o’clock position on the pump housing.
      3. Press the release tab on the connector and pull straight away from the pump to disconnect.
      4. Set your multimeter to the ohms (Ω) setting at 200 ohms range.
      5. Touch the multimeter probes to the two metal terminals inside the pump’s connector (not the wire harness side).
      6. Read the resistance value—it should measure between 8-12 ohms. A reading of 0 ohms indicates a short; an infinite reading (OL or 1) indicates an open winding.
      7. Grasp the pump impeller access cover (black circular cap, 3 inches diameter) located at the bottom center of the pump housing.
      8. Rotate the cover counterclockwise one-quarter turn until the tabs align with the slots.
      9. Pull the cover straight down to remove it.
      10. Insert a flat-head screwdriver (1/4-inch width) into the impeller slots visible inside the pump chamber.
      11. Attempt to rotate the impeller clockwise and counterclockwise—it should spin freely with slight resistance from the motor magnets.
      12. Inspect inside the pump chamber using a flashlight, looking for debris, broken plastic pieces, glass fragments, or food particles lodged between the impeller blades.
      13. Remove any debris by hand or with needle-nose pliers.
      14. Push the impeller access cover back into position and rotate clockwise one-quarter turn until it locks—you’ll feel it seat firmly.
      15. Reconnect the gray 2-wire connector by pushing it onto the pump terminals until it clicks into place.
      16. If resistance measured outside 8-12 ohms or the impeller won’t rotate, replacement pump motor (part number W10510667) is required.

      đź“‹ Step 5: Replace spray arms or pump if damaged

      1. Grasp the lower spray arm hub in the center of the dishwasher floor and turn it counterclockwise 1/4 turn (90 degrees) until it releases from the mounting post.
      2. Pull the spray arm straight up off the mounting post, which extends approximately 2 inches from the dishwasher floor.
      3. Position the new lower spray arm (part number W10536980) over the mounting post with the locking tabs aligned to the vertical slots on the post.
      4. Push down firmly and rotate clockwise 1/4 turn until you hear a distinct click indicating the tabs have engaged.
      5. Spin the spray arm by hand – it should rotate freely without wobbling or scraping sounds.
      6. Pull out the upper dish rack completely and set it aside on your work surface.
      7. Locate the spray arm attachment nut at the bottom center of the upper rack assembly – it’s a white or gray plastic hexagonal nut approximately 1 inch in diameter.
      8. Turn this nut counterclockwise by hand to remove it completely (no tools required).
      9. Lower the spray arm assembly down and away from the rack.
      10. Align the new upper spray arm (part number WPW10082853) water supply tube with the circular opening in the rack bottom.
      11. Thread the attachment nut clockwise by hand until finger-tight – do not overtighten as this can crack the plastic housing.
      12. Rotate the spray arm to verify smooth 360-degree movement without binding.
      13. Disconnect the dishwasher from power at the circuit breaker.
      14. Remove the lower spray arm as described above.
      15. Unscrew the 4 T20 Torx screws securing the pump cover at the dishwasher floor center.
      16. Lift the pump cover and filter assembly straight up to access the circulation pump (part number W10510667).
      17. Disconnect the white electrical connector on the pump motor by squeezing the locking tab and pulling straight out.
      18. Remove the 3 Phillips-head screws (#2 bit) holding the pump assembly to the sump housing.
      19. Twist the pump counterclockwise 1/8 turn and lift it out of the housing.
      20. Insert the new pump into the housing, rotate clockwise 1/8 turn until seated, then reverse steps 6-3 to reassemble.

      đź›’ Recommended Products

      Here are the recommended products for this repair: