We have a built in Electrolux 1590 that seems to have very little suction. I cleaned the filter, but in trying to put it back together, I need a picture of how it's supposed to fit. (We bought the house last April, and don't have a manual for the vacuum.)

Try somewhere like this

https://www.centralvacuumdirect.com/Electrolux-Model-1590-s/2944.htm

or here

https://www.centralvacuumonline.com/products/electrolux/

..

Here's a YouTube video describing how to troubleshoot a electrolux 1590 power head. It will cover all possibly faults.

https://youtu.be/mQQ8HKByy3c

Vacuum leak. Check all the hoses and connections for leak. Fix them and you will have nice strong suction again.

If you have dogs that shed, canister vacuums will always need cleaning out.. try to empty it before it's total full more often, this should prevent it from backing up so much.

On what unit? An extractor?

I took mine completely apart, removing every screw to get to the motor which was full of lint, hair and god knows what. I removed all the debris I could by hand, put it back together, and it works like new. I think debris gets in if the filter part is pushed too far down and the hole in the cup is open to the top part. My husband wanted to throw it out but I figured "what the heck". It's broken, it won't get more broken if I take it apart, it's only a year old.

There is a filter inside the main filter. Once that filter gets clogged it will loose suction. Pull the filter and clean it, you can wash it by hand. Turn the unit roller side up and check for a small screw cover that you can use a dime to loosen. This cover is used to remove the roller unit. Once out check and clean then check the gear assy. for miss-alignment.

yes try new battery it sound like a power problem.thanks

If you haven't got the new motor, the three stage has more suction. The 1590 CV had the three stage motor untin they changed to the two stage not long ago. You can get either one for your unit. The two stage should be a little less expensive.

There is most likely a clog in the hose. If the hose has poor suction the foot probably has poor suction as well seeing that the hose is what gives the foot assy suction.