A Harbor Freight parts washer is one of the best low-cost tools you can add to your garage, but anyone who’s used one knows it’s basically a blank canvas for improvement. Right out of the box, these washers will clean parts, but with a few smart upgrades, they can work better, last longer, and save you a lot of frustration.
In this guide, we’ll walk through the essential modifications for your Harbor Freight parts washer that experienced DIYers and mechanics recommend. From better pumps and filters to lighting, heating, and improved fluid management, these upgrades will take a basic parts washer and turn it into a tool you’ll actually enjoy using.
Here’s are the three modifications that I’ve done to my Harbor Freight parts washer as it sits; all of these, I’d consider them essential, unless you are blessed with a very large shop!
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Casters
Adding casters to your Harbor Freight parts washer is one of the simplest upgrades you can make, and it makes moving the unit around the garage a lot easier. I added these 2 in. Clear Polyurethane Light Duty Swivel Casters from Harbor Freight to mine, and they work great. Just keep in mind that the casters don’t come with nuts, so you’ll need to pick up four M8x1.25 nuts to secure them properly.
I mounted the casters directly into the bottom of the bent sheet metal on the parts washer, and while this does work, the metal is pretty thin. Over time, that can lead to wobbling or even bending if you roll the washer around with a lot of fluid inside. A better approach is to reinforce the bottom with either an extra piece of sheet metal or even a strip of sturdy wood before bolting the casters on. This spreads out the load and keeps the whole setup much more stable in the long run.
Drain/Petcock
One of the messiest parts of owning a stock Harbor Freight parts washer is draining the old solvent when it’s time for a change. From the factory, it comes with a simple hex head plug. The easiest solution is to install a drain or petcock so you can attach a hose and direct the flow neatly into a container. A 14mm x 1.5 drain petcock like this DEF F-106N Engine Oil Drain Valve on Amazon works perfectly for this setup. It’s not a commonly-available thread pitch, so you probably won’t be able to find something like this at your local hardware store.
The long nipple design makes it simple to slip on a length of hose, so when it’s time to swap out your solvent, you can do it without splashing everything around the shop. It threads right into the existing drain hole on the washer, and once installed, you can open or close it as needed without wrestling with messy plugs or tilting the whole washer to get the last bit of fluid out.
Solvent Filter
Keeping your parts washer solvent clean makes a huge difference in how well it works, and adding a filter is one of the best upgrades you can make. If you have some basic DIY skills, it’s easy to build your own filter system using a standard oil filter mount (found on Amazon), a spin-on oil filter (also found on Amazon), and some hose to connect everything together. The idea is simple: the pump pulls solvent through the filter before sending it back into the cleaning basin, keeping debris from circulating over and over again.
If you’d rather not piece it together yourself, there are ready-made kits available online. For example, this kit (we have no relation to this company) comes with everything you need to add a filter to your parts washer with minimal effort. Either way, a filter system will make your solvent last longer and keep the pump from clogging, saving you money and time in the long run.
Final Thoughts: Essential Modifications for Your Harbor Freight Parts Washer
With just a few simple upgrades like casters, a drain petcock, and a solvent filter, a basic Harbor Freight parts washer can turn into a much more capable and user-friendly tool. Each of these improvements makes maintenance and day-to-day use easier while also helping the washer last longer and perform better.
The next thing I’d like to tackle is upgrading the sprayers. I have a few ideas in mind, but I want to test them out myself before writing an article about it. That way, I can share what actually works rather than just passing along guesses or untested plans (and hopefully save you a few bucks, too).
For now, the modifications covered here will give you a cleaner, easier-to-use parts washer that doesn’t cost a fortune to build. With a few hours and some basic tools, you can take a stock unit and turn it into something far more efficient and enjoyable to use.
