Help -Can't Get My Juwel Filter Powerhead Back On!

[fishnovice]

Some time ago I accidentally broke the bottom of the 400GBpump for my Juwal 90 internl filter. I managed to stick it together with superglue but after a while it fell apart again so I bought a replacement part. The new part fits perfectly on the pump but I can't get the whole thing back onto the internal filter. Luckily I always keep spare filters so the fish are OK.
To be honest the pump has always been a pain to fit back on(dread filter cleaning days!) but it seems to be a powerful filter with lots of media sponges so I'd like to keep using it. It's also handy for keeping lots of spare sponges inside so they will be full of good bacteria whenever I need to set up a new tank or replace a dead filter.

 

[fishnovice]

Any ideas anyone?

 

[N0body Of The Goat]

So the pump impeller is spinning fine if you connect it to the mains, but you cannot "plug" the pump into the filter chamber?

If its like mine, the pump fits into a "case" with a diamond extension pointing downwards, which then fits into the filter socket. I can then reconnect the outlet and rubber bung through the chamber and onto the pump.

Does the "case" plug into your filter chamber socket? Juwel have got at least two variations of extension shapes.

A few months ago I bought what i thought was a great pump upgrade for my Juwel filter, a Bioflow 1500, only to find later that this pump only fits one older model of Juwel chamber (the Bioflow 6.0).

 

[fishnovice]

Precisely - pump impeller is spinning fine but can't "plug" the pump into the filter chamber socket. Seems to be the right shape and size but maybe 1mm too small.The thing is, the spare bottom part fits on to th etop part of the pump perfectly and pperas to be the right shape and size.
So what can I do?