SimpleHuman Wall Mount Soap Pump Dispenser Repair

The SimpleHuman wall mount dispenser is a mechanical pump that dispenses shampoo, conditioner, or body wash. Like most pump dispensers, they tend to get clogged and need to be flushed out. In my case, there was also a broken part.

This instructable will show how to dissemble and repair the pump. They are actually fascinating devices and you get a chance to see how they work.

The pump is held on to the wall mount using 4 screws and plastic brackets. Remove them and set them aside. Note the condition of one of my screws. The plastic is partially broken but not enough to worry yet about making a replacement.

The chrome decorative cover is held on using a a screw under a circular cap (one on each side). The caps are friction fit and can be gently pried off using a very thin prying tool or knife.

The plate is held on with screws on each side. Use a 3mm hex key to remove each screw. The plate will spring away from the dispenser and can be removed.

The pump base is made up of two sides held on by 3 long screws. Remove the screws and gently separate the two parts. There is a plate where the soap is dispensed that fits between the two sides.

Note: When you separate the two halves you will probably find one or two metal washers come out along with the handle.

The handle applies mechanical force to the plunger to dispense the soap. It has metal washers on each side. Note the bump which presses on the plunger.

The pump is connected to the storage chamber using a round piece of plastic tubing. Wiggle the pump off. Don't worry if the tubing stays on the base of the chamber.

Note the direction of the pump (although it's impossible to install it upside down).

The lid of the pump snaps on. Pry it off to get to the inner workings. The spring will push the inner parts up so be ready or things may fly around. It's pretty easy to see how they fit together.

Under the lid is a plunger that consists of several parts. There's an outer plunger that fits through the hole in the lid. Inside that plunger is another plunger that connects to a silicone seal

Note: In your pump, hopefully you won't have the problem I had with the outer plunger being broken into 3-4 pieces.

Both of the one-way valves are attached to the pump assembly using friction and o-rings. They are a bit stubborn to remove but can be gently pried off. Each valve is made up of a ball that blocks the opening and a spring that keeps the ball at the opening.

The one-way valves are the most interesting part of the pump in my opinion. The upper one has the ball pressing up to the reservoir and preventing the soap from entering. The lower one also has the ball pressing up to prevent the soap from being dispensed. When the plunger is pressed, the pressure causes the ball to block the reservoir while at the same time causing the ball at the dispenser to lower and allow the soap to flow. When the plunger is released, the partial vacuum pulls down the ball to the reservoir and allows more soap to enter the pump chamber to be ready to be dispensed.

Note: These are small and slippery parts to be careful when cleaning them not to lose them. Be careful with the vertical supports holding the ball in place. One of mine was partially broken.

As you can see, my dispenser had a lot of gunk in the pump and needed a good cleaning. It was pretty easy to do and the cleaned pump looks great.

This is a step you probably won't need to do but I designed a replacement pump in Fusion360 which I then printed. The inner hole was too small (as they often are) and rather than print multiple copies until I got the correct diameter, I just drilled it to size.

The one on the left is the broken plunger and the right is the 3D printed replacement.

This is my Thingiverse containing the design and stl files for the replacement part: 4596099

https://www.thingiverse.com/thing:4596099

Reassemble the pump reversing the steps. A few things to keep in mind:

1. There is a small gasket around the soap reservoir so be careful not to pinch it.
2. Place one washer on the piviot, place the handle (holding the bottom part to keep it parallel), then place the other washing on the top of the handle.
3. The pump assembly has a grove that aligns with the pump base.

There are about 35 pieces to this pump and the actual pump mechanism is pretty interesting. It's easy to dissemble and re-assemble with very few tricky parts. Just be careful with the parts, especially the inner pump parts, because they will be slippery as well as tiny and you don't want to lose any of them.

This is the third SimpleHuman pump that I've written instructables for (the other two were electro-mechanical). I hope you enjoyed this and let me know if you have any problems.

It's been a year and a half since I originally published this Instructable and I'm back again because I had another outer plunger fail on a different soap dispenser. It was almost an identical failure. This part is poorly designed and should have been made of better plastic or preferably metal.

I revisited here so I could refresh myself on how to disassemble and repair the pump. Because this is obviously the weak link in the design, I printed several additional copies so they'll be ready when the next pump breaks. The good news is that the repaired pump with my 3D printed replacement is still going strong -- it's only the original part that breaks.

As you can see, the broken pump leaked soap everywhere in the dispenser which needed to be disassembled and cleaned. I destroyed the second replacement (red plunger) because I was too aggressive when drilling out the hole. (I probably should go back and redesign the part with a bigger hole but I wasn't planning on having to print so many of them). Reassembled the pump and I'm good to go until the next plunger breaks.