Ive had this before.It was either air still in the system or a bad pump.And I dont care if you just got the pump,As a mechanic I have gotten plenty of NEW parts that were bad right off the shelf,Including batteries with bad cells.And I found to get all the air out,run it for a little with out over filling it,then let it sit for like a half hour, then start it again and slowly work the wheel from turn to turn.Keep trying that,letting it sit lets the bubbles in the fluid go to the surface and pop.If you dont do that and try and run it thinking it will work it will just keep re-sucking the bubbles back down into the system and recirculating them.You have to have no air in the system.After you figure it out add on to the post,Hope this helps

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