I need some input on my pool pump

Hi everyone. It's been a long time but I figured it wouldn't be too long :)

Anyway, I uncovered and started up my pool a few days ago and I think there are problems with the pump. I'm only getting about 1/4 of the water pressure. Regardless of which setting the filter is on the water just slowly flows out. At first I thought it was a problem with the filter but I'm now lead to believe that it may be with the pump (Waterco 1.5 or 2HP AGP).

Could it be the impeller? Maybe a ring or gasket inside of the pump? There were plenty of leaves and debri on the bottom of the pool and I could have sworn that when I first started backwashing to waste a few leaves came through. But noghint like what I should have be seeing on the ground from the waste output.

I've decided to run a line straight from the pump to the ground and bypass the filter. Is that a good way of making sure that the problem is with the pump and not somewhere in the filter or should I already know that the problem lies in the filter?

I'm about to go do that right now. 2nd question is once I've figured out that the problem is the pump how can I know what part it is? I plan on coming back to this site and checking in about an hour. I'll then break the pump down and see if I can see any bad looking parts or clogs. I know how to look for clogs but I'm not sure what I'll be looking for if a part has gone bad. What kind of cost would I be facing here? I appreciate as much input as possible on this. Thanks. I'll check back in a minute.

Water flows out of what? I ask because I had a filter problem where the water would flow out of the backwash hose even when set to "filter".

Water flows to the correct setting. It just flows very very slowly.

It does sound like an impeller problem, does the pump rattle more than normal?
Any possibility of partially closed valves? Blocked line somewhere maybe between skimmer and pump??

I got it fixed. I opened the pump to a huge glob of gobbiddygoook in the impeller (I guess that's everybody's been calling the propeller thingy). She's flowing like a champ now. Thanks a ton folks.

Good news!