pump won't prime with extra hose attached

[vwerz34]

The pump is old (maybe 18 years), but worked OK last season, and have just started using it again. Now, It will work OK when the skimmer just has a strainer basket, but when a hose is attached to the skimmer the pump won't prime (I assume that's the right term - it can't fill all the way, no flow). This happens even if just a short length of hose is attached to the skimmer. Without extra hose, the pump fills nicely, there aren't a lot of bubbles, maintains about 12 psi and seems perfectly fine. Could this be a leak, or should I just get a new pump? The only obvious leak now is on the output pipe where I did a temporary (2 years ago) repair. (I need to decide whether to replace the pump before repairing that.) Really need to be able to vacuum the pool!

[Themadczar]

I'm assuming you already know to submerge the hose and fill it with a jet before attaching it through the skimmer... So, every time I have trouble maintaining prime with a hose attached, there has been an obstruction in the hose or vacuum head (usually a large acorn). That's where I would start...

[vwerz34]

Yes hose is submerged, made sure it had no trapped air or blockage. Just an 8' length of hose will be too much for the pump.

[vwerz34]

Could it be that the end of the hose is down lower than the skimmer pipe opening, so in effect the pump is trying to draw water up a greater height?