Shop Vac Repair: Restoring Suction and Saving Money

Many of us rely on shop vacs for heavy-duty cleaning, but over time, they lose suction and eventually stop working altogether. In most cases, this decline in performance is due to lack of maintenance. Many users simply plug in their vacuums and expect them to function indefinitely without upkeep.

The Cause of Declining Suction

I own two shop vacs, both of which gradually lost suction over the years. I replaced the filters as recommended, but since I wasn’t the only one using them, I didn’t realize the real issue at first. The biggest cause of shop vac failure is improper filter management.

It’s standard practice to remove the filter when vacuuming up water or wet debris. However, when the filter is off, any dry material—including dust, dirt, and hair—can get sucked directly into the motor housing. Over time, this buildup severely affects performance.

A Common Mistake That Can Ruin Your Shop Vac

My wife frequently uses our shop vac to clean up after grooming our dogs. One day, she forgot to check if the filter was installed before vacuuming dry hair. As a result, dog hair was pulled straight into the motor. Unaware of this, I later installed the filter as usual and noticed a significant drop in suction.

Most people at this point assume the vacuum is broken and replace it. However, the problem is often fixable with a simple cleaning.

Disassembling and Cleaning the Motor

Both of my shop vacs have screws securing the motor assembly to the top of the unit. My smaller vacuum had six screws, while the larger one had eight. I decided to remove them to inspect the motor. After all, the vacuums weren’t functioning well anyway, so I had nothing to lose.

Upon opening the motor housing, I found a sealed motor with a fan assembly. The motor is sealed to protect its internal components when vacuuming wet materials. However, the fan, responsible for creating suction, was completely clogged with pet hair and debris.

I thoroughly cleaned out the debris, washed the components, and used an electric motor cleaner before reassembling everything. When I turned the vacuum back on, it was much quieter, and the suction power was fully restored. I repeated the same process on my other shop vac and found similar debris buildup from wet materials wrapped around the fan assembly. After cleaning, it performed like new.

Why This Maintenance Isn’t in the Manual

Surprisingly, neither of my shop vac manuals mentioned cleaning the motor housing as part of routine maintenance. The process is simple—just a few screws and a few minutes of work—but manufacturers may not highlight it. After all, if more people knew how to fix their vacuums, they might not buy replacements as often.

If your shop vac is losing suction and the motor assembly is removable, take the time to open it up and clean it. With just 15 minutes and a screwdriver, you can save yourself a significant amount of money. In today’s economy, every bit of savings counts!