How can I fix my Whirlpool washing machine WFS1275CD?

I have the clean pump light continually coming on, and my Whirlpool front loader washing machine (WFS1275CD) stops mid spin cycle and won't continue spinning or draining. I have cleaned the filter on the bottom right of the machine and it didn't correct the problem. I removed the hoses in the machine and cleaned but was distracted by my toddler and am no longer sure how to place the ping pong ball back into the hose (ball on the drum side of the pipe insert or under the insert and on the pipe side). It doesn't seem to fit in a set place. Any help would be most appreciated.