How to replace a Whirlpool dishwasher spray arm water supply tube WPW10340745

Is your dishwasher leaving you with less-than-sparkling clean dishes? A faulty spray arm water supply tube might be the culprit, causing insufficient water flow to your upper rack. Dive into our step-by-step guide, complete with a how-to video below, and learn how to replace this essential component to restore your dishwasher’s performance in no time.

Replacing the spray arm water supply tube (part #WPW10340745) is a repair for Whirlpool, KitchenAid and Maytag dishwashers when the upper rack dishes are not getting properly cleaned. This tube supplies water to the middle and upper spray arms and also holds the upper arm in place. Over time, cracks and clogs can develop in the supply tube, preventing adequate water flow.

WATCH: How to replace spray arm water supply tube

How the spray arm water supply tube works

It helps to understand the function of the spray arm water supply tube. This curved plastic tube is mounted at the back interior wall of the dishwasher tub. The top end connects to the water inlet at the bottom of the upper spray arm. The middle section feeds water to the rotating middle spray arm. The bottom end sits in a bracket near the dishwasher floor, positioned under the lower spray arm.

When cracks and obstructions occur in the supply tube, water flow becomes restricted. Dishes in the upper rack will not get properly sprayed, resulting in debris and spots left on glassware, cutlery, plates, and more after a wash cycle finishes. Replacing this affordable part restores normal dishwasher cleaning performance.

READ MORE: How Does a Dishwasher Work?

Safety first!

Before proceeding with this spray arm tube replacement job, you need to disable the power to the appliance to prevent shock or electrocution. Start by unplugging the dishwasher from the electrical outlet under the sink or shutting off the circuit breaker controlling the unit.

Additionally, turn off the hot water supply line attached to the dishwasher fill valve. This is the braided stainless steel hose mounted on the left rear side. Turning the shut-off valve clockwise completely cuts off water flow.

Safety first! Make sure both power and water are fully disabled before disassembling any dishwasher components.

READ MORE: 8 DIY Safety Tips

Tools and supplies needed

This repair job takes just a few tools and minutes to complete. Gather the following items:

• Flat blade screwdriver
• Replacement spray arm water supply tube (part #WPW10340745) – Take your model number to AppliancePartsPros.com to locate the correct part for your model.
• Towels – for catching water drips

Step-by-Step Installation Guide

Replacing this tubular plastic part requires disassembling some dishwasher racks and interior components. Carefully follow these step-by-step instructions to smoothly replace your faulty spray arm supply tube:

Remove the top and bottom dish racks

The first repair step involves taking out both sliding dish racks to clear space for accessing the back supply tube:

1. Pull out the top dish rack completely to extend the rollers. Take care not to place pressure on the sides, as too much weight can twist and deform the metal.
2. Locate the two gray plastic rack stoppers inserted into the top of the upper rack rails. Take note of their position and orientation.
3. Insert a flathead screwdriver into the square notch on each stopper. Gently pry upwards to release the clip while pulling out the stopper. Set both aside in a secure place.
4. With the stoppers detached, slowly pull out the upper rack to remove it completely. Set this dish rack aside on a towel without allowing the rollers to touch the floor.
5. Follow the same process to fully remove the bottom rack as well. Pull out slowly, keeping the wheels aligned on the roller tracks.

Removing both dish racks clears space to access the spray arm water supply tube positioned along the back interior tub wall.

READ MORE: Why It’s Best to Choose OEM Over Aftermarket Parts for Appliance Repairs

Detach the lower wash arm and filter screen

Before accessing the supply tube, a few additional components need to be temporarily removed:

1. Grasp the lower spray arm nozzles and turn the large plastic retaining nut 1/4 turn counterclockwise. This releases the arm from the water supply tube so you can detach it straight upwards.
2. Locate the cylindrical fine filter assembly on the dishwasher floor near the lower spray arm. Note the orientation of the handle before prying off the cover. Insert a flathead screwdriver into two notches and pop off the screen. Set aside carefully.

Taking off these dishwasher components allows clearer access to the spray arm supply tube without anything obstructing your workspace.

READ MORE: My part is no longer available! What do I do now?

Release the old spray arm water supply tube

With all removable interior parts detached, start disengaging the old supply tube:

1. Locate the upper end near the ceiling where two small locking tabs are inserted into slots. Take note of this position. Insert the flathead screwdriver into the slots to gently pry and release the two clips.
2. Hold the tube firmly and maneuver it leftwards to unlink the top end. Be careful not to bend or crack the old plastic part.
3. Rotate focus to the middle part of the tube which presses into a centered bracket. This portion also clicks into place. Carefully pry the mid-section loose with the screwdriver to detach from the metal brace.
4. Finally, tilt the entire tube downward from the top while releasing the two lower brackets hooked at the bottom. Apply pressure sideways with the blade to free the last end and fully remove the tube.

READ MORE: 4 Simple Ways to Reduce Kitchen Waste

Transfer bracket to new spray arm tube

Before inserting the replacement spray arm water supply tube:

1. Examine the old tube and locate a rectangular white mounting bracket midway along the curvature.
2. Push the bracket off the old tube to slide it out completely.
3. Take the new spray arm tube replacement part. Align and gently press the bracket piece lengthwise onto the middle to transfer it over. This helps secure installation.

READ MORE: Best Loading Techniques For Your Dishwasher

Reconnect the new spray arm tube

With the mounting bracket installed on the replacement tube, you’re ready to reconnect it to the dishwasher:

1. Orient the new tube correctly based on the original position, with brackets and notches facing the proper direction.
2. First, slide the bottom end clips into slots on the tub’s base. Apply pressure as needed to fully snap into place.
3. Pivot the tube upwards while aligning the middle bracket section into the centered metal support. Firmly press until you hear a click indicating engagement.
4. Lastly, tilt and maneuver the top of the tube until properly seated into the upper supply tube. Both side locking tabs will snap into the waiting slots when aligned accurately.

Check that the entire tube feels securely installed along all connection points before moving to the next steps.

READ MORE: How to Clean a Dishwasher

Replace remaining dishwasher components

With the upgraded spray arm water supply tube mounted correctly, replace all other previously removed interior parts:

1. Pick up the cylindrical fine filter assembly and place it over the floor outlet port. Match the original orientation you observed initially. Apply pressure around the rim to relatch all 4 clips.
2. Reattach the lower spray arm below by setting it into position and rotating the nut clockwise about 1/4 turn until tight.
3. Carefully realign and slide in the bottom dish rack first. Ensure the back wheels roll smoothly along the tracks.
4. Similarly, replace the upper dish rack as well by rolling back the sliding frame. Mind the sides to prevent bending.
5. Find the two gray rack stoppers and insert all four locking tabs simultaneously so the clips snap back into the rails. This secures rack position.

With all components replaced, you’re ready to test operation!

READ MORE: Surprising Things That Can & Can’t Go in the Dishwasher

Restore power and water to the dishwasher

The spray arm tube replacement process is complete! Finish by:

1. Reconnect the dishwasher to electrical power at the breaker panel or outlet.
2. Rotate the water supply valve counterclockwise completely to enable water flow.
3. Run a test cycle empty to verify no leaks exist at the new part or surrounding connections. Extend the cycle to confirm adequate spray from the wash arms.
4. Reload dishes and glasses onto the racks and wash them as normal. Monitor that upper rack contents get fully cleaned now.

READ MORE: Surprising Things That Can & Can’t Go in the Dishwasher

More information

Thanks for reading! We hope this article helped you replace the spray arm water supply tube in your dishwasher.

If you still need some replacement parts, grab your model number and head over to AppliancePartsPros.com. We offer over two million parts and most orders arrive in two business days. If you need some help with finding the right part or placing an order, you can contact our team at 1 (877) 477-7278.

While you’re waiting for your new part to arrive, you can explore our DIY blog and watch thousands of video tutorials on our YouTube channel.

Be sure to follow us on Facebook, Twitter and Instagram to see our latest repair guides!