Keep searches simple. Use keywords, e.g. "leaking", "pump", "broken" or "fit".
I have experianced these knobs are easily broken.
Before installing the new part I made a metal coller to fit around the bottom of the stem. It gives the knobs the support that is lacking on the original part. I did this to all the knobs previosly and never had any more broken knobs.
Ordered new part--on line help said pull all remaining parts out--small pair of plyers and yanked internal parts out--the new part just slipped down over the u-post and back in business--couldn't have been easier
The old grease filter was removed and the entire downdraft was cleaned. The new filter was slipped in. It is so nice to have the old one out. I am so appreciative of finding this part. :-)
Remove existing knob by pulling straight up noting direction of indexing mark. Replace with new knob by aligning index mark and pushing straight down. Presto...done!
This repair was extremely easy. I was able to lift off the broken fan knob with some pliers. The new knob easily fit and the new knob works like a dream!