Why would a sleve back out on a MP40???

[Lowefx]

So I've noticed one of my mp40 have gotten noisy, similar to being out of ballance. The cover flew off of it 2 days ago, and I just got around to putting it back on, but I couldn't because the white "sleve" over the metal rod is extended over the metal rod about 1/4. I tried hammering it back down, but that sleve splintered similar to ceramic.

Why would this happen?

Is this repairable?

TIA

 

[SteveMM62Reef]

Replace the part, MP40QD Wet Frame Assembly?

 

[Lowefx]

Replace the part, MP40QD Wet Frame Assembly?

Yes, I have extra. But I wanted to know if this is typical or normal for the MP40's? Or am I doing something wrong?

 

[SteveMM62Reef]

Vinegar will destroy the Pump. How old is the Pump, could it have ingested something to make it run hot? On commercial pumps at work, if they ran hot, it would damage the ceramic seals.