Circ motor on Bosch SHU9925 (5/2002 factory date) wasn't operating (and was emitting a louder than normal hum in the weeks prior to shutting down). When I took it apart, problem was obviously the impeller. The green endpiece was fused practically solid to the front housing, and there were a considerable number of PVC shavings, including green endpiece shavings that remained stuck to the housing, and housing shavings that remained stuck to the impeller piece.

Once I separated the endpiece from the housing and cleaned things up, the circ motor ran fine, except for that louder than normal hum, which I'm guessing is because there's still some friction and/or misalignment between the impeller endpiece and the housing. I know this is just a temporary fix and am ordering a new impeller kit. My two questions: First, do I need to replace the front housing as well (I'm hoping not to, because it in turn means redoing the hose/clamp connections, but maybe it's foolish not to). Second, the impeller kit includes the carbon ring/spring that goes in the middle of the rear housing, so how hard is it to get the old ring/spring out and insert the new one (and/or do I need to get a new rear housing as well)?

Am waiting to see if anyone has any responses before ordering the impeller kit and anything else I need -- so thanks much for any answers to the questions above or any related advice.

P.S. In case it's helpful, I'll try pasting this PDF diagram of the assembly, from a manual I found elsewhere in these forums.