Pressure Problem

[Watermom]

Thanks for coming back to tell us what the problem was. So many times, there are threads where people are scratching their heads trying to figure out what the problem is and then we never hear the conclusion to the story. When people do come back and report the resolution to their problem, it helps others in the future who may be reading this thread. So...... thanks!

[PoolDoc]

The new pump I installed came without the diffuser.

What do you mean? In the image below, #6 is the diffuser:


But self-priming centrifugal pool pumps cannot function properly without this part. I haven't tested it, but I'm pretty sure this pump (and most pool pumps) wouldn't pump at all, without the diffuser.