Problem w/pump

[darock73]

My Sedra 5000 pump looks like it's malfuctioning. There are air bubbles coming out from the back. It has a mod pin wheel. Bought it used W/ASM G3 Skimmer.

 

[OzoneParkGuy]

I never had a problem with a pump, thankfully...but I'll try an help. Any unusual noise you hear comming from the pump? If you hear noise replace the impellar.. sometimes the gasket o ring on the impellar flatens out or the nipple wares thin. In that case needs replacement. In your post you state moded impellar and used unit. Was it a diy modded impellar with mesh attached? If so, the mesh screening might have become dislodged or a piece broke off. I would open the unit up carefully as to not strip any screws or brake any delicate parts and look at the impellar assembly and housing unit for it being warn.. taking notes as to what goes where and replace exactly as you took it apart. It may just need cleaning. Distilled White Vinegar and water does wonders for any build up. Hope this helped some.... Good Luck and hopefully others will chime in. Laterzzz..