pump impeller binding

[schoch79]

Hi guys. Just getting back into the hobby again after a break and noticed that on my sicce pump for my protein skimmer the impeller is binding. To explain a little better, when I plugged it in it just hummed. So I removed the cap that holds in the impeller and plugged it in again. The impeller turns freely. So I assume that means the motor or anything isn't shot. When I replace that cap it doesnt work again. The only way I can explain it is the fitting seems too tight or something and wont let the impeller turn. I looked over everything and it all seems clean. Am I missing something? Do I need to just lubricate something? Am I stuck getting a new pump/impeller assembly? Thanks for the help.

[whiteshark]

My Sedra pump on my ASM did the exact same thing after sitting for years. Turns out the magnet part of the impeller distended. Take the impeller out and look at the magnet. If it's not perfectly cylindrical, you need a new impeller. I replaced the impeller on my pump with a new one and it works fine.

[schoch79]

Thanks I'll have to look at that.

[sporto0]

Clean or I should say scrape your post smooth, calcium & other metals tend to build up on them, not allowing free rotation of the impeller, if it is a ceramic post, use much caution when working on it, they snap all too easily.

[schoch79]

Yeah I've broken one or two of them myself. Nothing gets me madder. Just for a follow up, everything works fine now. Turns out there is a ceramic "bearing" of sorts that fits on the end of the shaft and into the rubber stopper thing at the end. When I was first looking at it I thought the bearing and the shaft were one piece since they were stuck together at first. I paid special attention to cleaning that part in particular and no problems now. Thanks again.