How to Replace W10403802 Washer Drain Pump on Whirlpool & Maytag Washers — Step-by-Step

Your Whirlpool WTW8000BW0 won't drain. Water's sitting at the bottom of the tub after the spin cycle, and you can hear a faint humming sound—or maybe nothing at all. You've checked the drain hose for kinks. You've cleaned the filter. The culprit? A failed drain pump.

The W10403802 drain pump is one of the hardest-working components in your washer, running during every cycle to evacuate water. When it fails, you're left with wet clothes and standing water. This guide walks you through replacing it on models like the Maytag MVWB850YG1, MVWB950YW1, and Whirlpool 7MWTW8800AW0.

What You Need Before Starting

This isn't a difficult repair, but you'll need some basic tools and about an hour of your time. Here's what to have ready:

• 1/4-inch nut driver or socket set
• Flathead screwdriver
• Needle-nose pliers
• Towels (for water spillage)
• Shallow pan or bucket
• Work gloves

Estimated Time: 45-60 minutes

Difficulty: Moderate

Safety First

Unplug the washer from the wall outlet before you start. Don't just turn it off—physically disconnect it. Water and electricity don't mix, and you'll be working near electrical connections. Also, expect residual water in the pump housing—have those towels handy. If your washer has been recently used, let it sit for 10 minutes to allow any hot water to cool down.

Step 1: Access the Drain Pump

You'll need to access the pump from inside the washer cabinet. On most Whirlpool and Maytag top-load models like the MVW8850YG1, the pump sits low in the cabinet, accessible from the front or bottom. Tip the washer back slightly against a wall—this gives you clear access to the base. You might see a front access panel secured with screws at the bottom corners. Remove these screws with your nut driver.

Step 2: Disconnect the Hoses and Wiring

Locate the drain pump—it's a black or gray housing with hoses attached at the inlet and outlet. Use your pliers to squeeze and slide the spring clamps off each hose connection. Have your pan ready. When you pull the hoses free, water will drain out. Disconnect the wire harness by pressing the locking tab and pulling straight off. On the 7MMVWB950AG0, there's sometimes a zip tie securing the harness—snip it if present.

Step 3: Remove the Old Pump

The pump is typically held in place by two or three mounting screws or a twist-lock bracket. Check your specific model—some Maytag units use a quarter-turn mounting system where you rotate the pump counterclockwise to release it. Others have direct screw mounts through the pump housing into the cabinet frame. Remove the fasteners, then carefully wiggle the pump free from its mounting position.

Step 4: Install the W10403802 Replacement Pump

Position your new W10403802 pump in the same orientation as the old one. The inlet and outlet ports should align with your hoses—don't force anything. Secure it with the mounting screws or twist it clockwise if it's a quarter-turn mount. Reconnect both hoses, sliding the spring clamps back into position about 1/2 inch from the hose ends. Snap the wire harness back onto the pump connector until you hear it click.

Step 5: Reassemble and Test

Reattach the access panel if you removed one. Lower the washer back to its normal position. Plug it back in. Run a drain and spin cycle without clothes—just let it run with the water that's already in the tub if any remains, or run a rinse cycle. Listen for the pump motor engaging. You should hear a strong, consistent hum, and water should evacuate from the tub within 2-3 minutes. Check underneath for any leaks at the hose connections.

Testing After Installation

After your initial test cycle, run a full wash with a small load. Monitor the drain cycles—both the mid-cycle drain and the final spin drain. The pump should operate smoothly without unusual grinding, rattling, or hesitation. If you notice water remaining in the tub after the spin cycle, double-check that your hose clamps are tight and that the outlet hose isn't kinked where it connects to your home's drain line. On models like the MVWB950YG1, a kinked drain hose can mimic pump failure symptoms.

Frequently Asked Questions

Will this pump fit my Whirlpool Cabrio or Maytag Bravos washer?

Check your model number against the compatibility list. The W10403802 replaces several part numbers including WPW10403802 and AP6020990, and it's designed for specific Whirlpool and Maytag top-load washers manufactured between 2011 and 2018. If your model number matches units like WTW8000BW0 or 7MWTW8800AW0, you're good to go.

How do I know if the pump is actually bad and not just clogged?

Remove the pump and inspect it before ordering a replacement. Spin the impeller by hand—it should rotate freely without grinding. Check the inlet for debris like coins, socks, or lint buildup. If the impeller is jammed or won't spin, try clearing it. If it spins freely but the pump still won't drain during testing, the motor windings are likely burnt out, and replacement is necessary.

Can I test the pump electrically before installing it?

Yes. Using a multimeter, check for continuity across the pump's electrical terminals. You should read between 5 and 15 ohms of resistance. Infinite resistance means an open circuit—the motor is dead. You can also apply 120V AC directly to the terminals (carefully, with the pump off the washer) to see if it spins, but only do this if you're comfortable working with live voltage.