Grundfos MQ 3-45 booster pump reassembly issue

[brian62c]

Hello,

I had to remove the inlet end of my booster pump to get a new non-return valve fitted - but now I can't get it back on! It doesn't quite push far enough into place to allow me to get the three screws back in to fix it on. I've looked at the Grundfos servicing video on Youtube but unfortunately it doesn't offer me any clues as to why mine isn't co-operating. Any tips gratefully received. I'll try to upload a photo. Cheers.

 

[just pumps]

If it came with a new seal or O-ring are you certain that the old seal isn't still there.

 

[brian62c]

Thanks for the suggestion but yes. No new seals or O rings. There are only two - one big one which goes round the whole pump end and one smaller one which goes on the yellow part in the middle.

 

[brian62c]

Okay, finally sorted it. must have been the very act of posting on here inspired me! The circular yellow plastic piece which, in the servicing video, fits into the metal end housing, is stuck in the main body of the pump on mine (see my photo). It can be turned by hand, anticlockwise, as part of the central black plastic cylinder-shaped piece. It seems it's critical which way up the yellow plastic piece is, because of the flange-type plastic bits sticking out of it around the centre. I think it needed the straight piece to be at the bottom (but it may have been the other way up - sorry, can't remember!). Anyway, once I had it the right way up, I was able to get the three fitting screws in place and tighten them, then fit the outer metal retaining band. Job done. Fingers crossed for no leaks now