Brand: Whirlpool
Model Number:WFW9500Tw03
Main Symptom: partial drain
What happens & when:
Error Code (if any):F27
Parts or tests already tried: New pump motor M75. I replaced the pump motor. Removed hose from drum to pump. Also remove the hose from pump to the back of the washer. And hose from back of the washer to sandpipe. Everything is clean. So it basically only 3/4 drains. You can still hear the pump running but initially it will pump water and then stop pumping water but the pump is still running. Doesn’t make any sense. It’s almost like it’s losing prime. I’ve double-checked sandpipe drain. It’s at proper height and clear of no obstructions.
Photos / video link:
Hello, if you have replaced the motor and you continue to hear the motor running, there has to be a floating restriction in the drain system. There may be something floating around in the tub that moves in and blocks the drain as water is being pulled out of the tub. The only way to fix it would be to take the tub apart. Try again to remove the tub to pump hose and see if you can fish whatever is in there out.
Interesting. I understand what you’re saying about something being clogged in the tub to hose. It’s just weird that there’s water in the hose front pump to tub. And from pump to the back of the washer and it still won’t push that up
Think of it like this. There is water from the tub to the standpipe. As soon as you start the washer in drain mode, it stats pumping water out, something inside the tub moves over and tries to leave the tub but is blocked because it can’t get through he opening, it shuts off water flow. When you stop the washer, the restriction moves away from the opening and water then can fill the void. I have seen this before. I don’t know for sure this is the problem with your washer, it just sounds familiar.
Understood. I’ll remove the tub hose tonight and take a look. When I disconnected it from the pump it was clear there but something has to be restricting it on the other end. Thanks for the info 
Update:
Removed the tub two hose pump. Spun the tub while looking in the bottom with a flashlight didn’t see any obstructions. I’m starting to think maybe I just have a new defective pump.
The impeller would be what you can look at. It should not spin independently of the shaft.
Update 12/29/25
Replaced with OEM pump. All hoses are clean with zero blockage. New sandrain. After spin cycle/ drain has 3 cups of water left in hoses. At this point only thing left that I think would cause this issue is control board or pressure sensor switch 
There will always be some water left in the hoses, which acts as a trap to keep gas from the standpipe from entering the washer. You just don’t want water standing in the bottom of the washer where it can come into contact with the clothes.
Yeah I totally understand. The issue that I have though is I get random f27 which leads me back to the drain issue. That’s why I was weaning towards the pressure switch