I collect/repair all different sorts of vacuums and I can tell you that the vast majority that I've collected, scrounged etc because they weren't "working" properly anymore is because there is something caught somehwere that is blocking the airflow. Either in the power nozzle or the vacuum hose, or in the case of uprights somewhere in the tubing that goes from the beater bars up to the bag.
Believe it or not most are usually found with bags so full of debris the bag is almost ready to explode or tear and that is quite common as well. But that's probably not your case if you change your bags regularly

Here's what to do.

You have to check each section for a blockage..

The opening where the hose inserts into the vacuum up to the bag itself. On many vacs can usually just look and see

Check the wands visually
Check the hose, this may be difficult if there is a curve in the hose with a handle on the end. But if attach just the hose to the vacuum while it is running and notice a big difference in sound or suction there's a chance the hose is blocked

Check the power nozzle (usually the culprit)

To check the power nozzle might entail taking the base plate off just like you would have to to change the roller or the belt. Once it's off you can usually see or poke a piece of wire thru the airway to dislodge something stuck in there. Depending on your comfort level or abilities you may want to get someone else to do this for you.

I forgot to ask....do you notice this more when you're using the attachments or the power nozzle... could it be that the bristles on the roller bar are just worn down so it's not picking up on carpet as well as it used to.

Do you have animals? If so you should regularly clean the brushes. Remove the brush and clean it and also the space where it goes. The lady at the vacuum repair shop told me this and all I could think is Oh great, one more thing to clean!

Hi. Thanks for the tips. PK guy -- I did as you instructed but didn't find any blockage. Thanks for responding.

If your vacuum cleaner was clogged,it would eventually shut itself off, to cool down. It is not going to be a worn brushroll, because the bristles will not wear down that fast, in your situation.

You are going to have to see if you have a leak somewhere. A leak in the airflow path will decrease suction at the cleaning end. Two major places are at the canister itself. Turn the vacuum on, then feel and listen for air. Feel around the bag compartment lid. The gasket may be damaged. The slightest indent will allow air to escape. Sometimes the end of the paper bag gets caught when closing the lid, leaving a gap for air to get sucked in.

Another area is where the front wheel is located. When this vacuum cleaner is dropped on its front wheels, the casing can crack. This means that some air will get sucked in the bag compartment here instead of at the hose. Listen and feel around for the movement of air from the wrong places.
Feel around for leaks in the hose.

If all else fails, you can also have a motor problem. This includes the fan. You will then have to bring the vacuum cleaner to a repair shop.

Tip-use the microlined bags or the HEPA bags, because they will give your Kenmore more motor protection. Also make sure that you clean the premotor filter with every bag change. This just means tapping the dust out of the filter. Replace the final exhaust filter regularly.

The same thing happened to my last two Kenmore canisters. I could tell the suction was getting less and less and I am done with them. I think it is pin holes in the hose that come over time. My is only a year old also and I noticed a definite difference from when I first got it. I won't buy another one.

If it is an upright, it could be something as simple as a stretched out belt. I think the Progressive canisters have a cogged belt so the slipping belt wouldnt apply.

There does not seem to be any blockage, it's just that the once powerful suction has drastically diminished. Boo-hoo. I'm thinking about taking it in to a vacuum repair shop or should I call sears? The darn thing is just one year old! Maybe I should replace the hose (although this is very expensive).

I have 2 Kenmores. The 1st one I purchased in 2000 was an upright. It sucks so good that I went out and bought a canister in 2002. They both pick up really well. Now I read somewhere that Eureka was going to start manufacturing Kenmores. That was about 3 or 4 years ago and if your Kenmore was made by Eureka it is garbage. I will never own another Eureka, EVER. Eureka vacuums=garbage!

It's hard to say whether it's worth taking in for repair if the repair is going to cost near the price of a replacement. What model # is it? There should be a label or tag somewhere on the bottom/back or inside where the bag goes telling you the model and serial number.

domesticah

It looks like, from your last post, that you did not check to see if there are any leaks. Do not go out and purchase a hose if you do not know what the problem is. Take the vacuum to a reputable vacuum repair shop and have them look at it. They can turn it on right there and tell you what is going on. They will be able to get parts for it unless it is the motor or any part of the plastic casing. They can find a hose for it. I know what vacuum you have. If they were knowledgeable enough, they could figure out the motor replacement.

elbits

Eureka did make some models for Sears a few years before the dates you are speaking about, but they do not now. TTI(Royal, Dirt Devil, Regina, Hoover,Vax)has come out with some models for Sears. Presently, they are most of the Kenmore uprights. Sears has continued selling the popular Beltless uprights made by Panasonic.

Hi geguymw,
I did notice a little air coming from the place were the hose connects with the wand/tube -- there also a little slider thing there you can engage to lessen the suction (for what purpose I do not know). There is also a little air coming from the button in the wand. It is so minimal that I can't imagine that this alone would affect the suction. Otherwise there do not appear to be any other leaks. Thanks for your advice. It is a Kenmore Progressive Model 116.

Actually the full model Number is 11625614506 and I am beginning to think I might have a broken belt?

If the brushroll is not turning when the power nozzle is turned on then you have a broken belt. An easy cheap fox.

How did we go from lack of suction to brushroll belt broken? Now I would not be surprised if you tripped the overload protector in the power nozzle.

Turn the vacuum cleaner on. Do you hear the motor in the power nozzle? If you do not, then press the square button on the top of the power nozzle. The power nozzle should now start running. This is the overload protector or circuit breaker reset button. If the brushroll slows down or something gets jammed in the power nozzle, the overload protector stops the power nozzle. This will protect your power nozzle and anything getting caught in the nozzle.

If the power nozzle motor is running, look to see if the brushroll is turning. If it is not, then you have a broken belt. I would really be surprised if that belt was broken, since they tend to last a very long time and your vacuum is not that old. Your vacuum uses a poly-V belt.

You said, "...there also a little slider thing there you can engage to lessen the suction (for what purpose I do not know)".
You want to use this suction control when you vacuum things like lampshades, draperies, small, thin rugs,etc, so you can decrease the suction. When you want full suction, keep the suction control closed.