Vacuum Cleaner Had an Unserviceable Filter

Recently our vacuum stopped working as well as it used to. Granted, we track in dirt from the garage, and have little kids and a dog running around; but the vacuum should still be able to do its job.

I started the investigation with my first gut feeling -- the belt was loose, or maybe the scrubber was jammed with hair and carpet fibers. The belt checked out fine and I removed a Persian rug's worth of thread and hair from the roller. Next, the filter was replaced and everything washed out of the bag/inlet area. Nothing worked -- the vacuum was just not pulling as hard as it did when it was new.

So, determined to not spend money on a new vacuum, I decided to go all mechanical engineer on the beast. I was suspecting loose clearances in the vacuum's centrifugal pump area, clogged internal lines, or some sign of motor damage/overheating that could be lowering shaft RPM. What I found made me want to kick someone.

The hunt started with the removal of about 18,000 Torx screws, scattered across the seven continents of the giant extrusion known as the back of my vacuum. I only ended up breaking one tab that was sneakily hidden under the cord wrapping. I certainly drive cars that have more self-inflicted damage than that. Accessories, hoses, pivots, cup holders, all of it had to come off before I could get far enough in to find the vacuum itself.

Finally, the heart of the machine slumped out onto the bench. I worked the shaft back and forth, nothing seemed too loose or tight. No debris was filled in the chamber or inlet of the pump. I even used my air compressor to spin the pump over for a second -- no grinding or much resistance to movement at all. My problem didn't seem to be coming from this end, and I knew the entire filter and upper hose assembly were clean.

OK, so the air can get into the vacuum without much problem -- could it be having trouble getting it out? The design seemed smart -- the outlet of the pump wraps around the motor windings to cool it with outlet air. A thin foam filter lays around that assembly and then out through openings. Then, I noticed something covering the outlet openings. It was a dense, felt-like material and was completely clogged with dirt and debris. The felt was certainly much more dense than any of the filtering elements in the system, and was about 1/16-inch thick. The pressure drop had to be pretty significant compared to the rest of the system. I started washing it, planning on putting the piece back in and seeing if my problem was solved. I got to thinking; this is only going to happen again as the dust builds up from day-to-day use. So instead, I left the felt out and reassembled the machine. It is back to acting like new and might even have a little more power now.

The moral of the story? Try not to place unserviceable filters in a device that moves lots of dirty air. In this case the "filter" was almost more of a safety element, as it kept small things (paperclips, pennies, forks) from stabbing directly into the plastic slots on the front of the vacuum and into the motor windings.

This concern could have been alleviated by designing the slots in a waffle pattern, instead of long, narrow channels. If a filter on the outlet was really necessary (as I've had vacuums with a HEPA filter in this location) try to make it replaceable. Of course, the whole design could very well be a wise marketing move to make this a vacuum that only works for a few years and then ends up in the trash.

Do you remember some of the older, all-metal vacuums? These were around in the day when vacuum repair was a "thing" and not just what frustrated engineers might do in their time off. Hopefully this story can help us all feel a crack on the knuckles the next time we're thinking of hiding something that should be serviceable, deep down in a machine.

Tell us your experiences with Monkey-designed products. Send stories to Lauren Muskett for Made by Monkeys.

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