Washer Bottle Relocation Kit

This is a washer bottle relocation kit designed for the Mazda MX-5 / Miata NA and NB.

I designed this tank to move the washer bottle to a cleaner position in the engine bay while keeping the installation simple. The kit uses an existing hole on the car for mounting, so no major modification is required.

Printing Recommendations

I printed the main tank in PETG for better heat and chemical resistance compared to PLA.

My print settings:

Material: PETG
Nozzle: 0.4 mm
Wall/perimeter count: 8 walls
Top layers: 8
Bottom layers: 8
Infill: high / solid-style print recommended

I used a high wall count and increased top/bottom layers to make the part as solid and watertight as possible. For a fluid container, print quality and layer adhesion are very important.

The cap is designed to be printed in TPU. On my car, the TPU cap seals well and does not leak.

Nut Insert During Printing

A standard nut is used inside the mounting point.

You need to pause the print in your slicer before the top of the nut pocket is closed. When the printer pauses, place a normal metal nut into the pocket, make sure it sits flat, and then continue the print.

The print will cover the nut and trap it inside the part. This creates a strong mounting point and prevents the screw from threading directly into plastic.

Recommended steps:

Slice the tank and check the layer preview.
Find the layer where the nut pocket is open and ready for the nut.
Add a pause at that layer in your slicer.
When the printer stops, insert a standard nut into the pocket.
Make sure the nut is fully seated and not higher than the printed surface.
Resume the print.

Be careful while placing the nut so you do not move the part on the print bed. Also make sure the nut is seated correctly, otherwise the nozzle may hit it after the print resumes.

Installation Notes

The tank mounts using an existing hole on the car. After installation, you can add foam tape or similar padding to the bottom/contact area of the tank if you want to reduce possible vibration or noise. On my car it did not cause any annoying noise, but adding padding is a good optional improvement.

The washer pump stayed in place well on my setup. However, if you want extra security, I also included an optional pump holder. You can print it separately and glue it to the tank. It holds the washer pump very tightly.

Included Files
Washer bottle tank
TPU cap
Washer for the screw
Optional washer pump holder
STEP file for modifications

I am also sharing the STEP file, so feel free to modify, improve, or adapt the design for your own setup.

Required hardware:
1 M6x10 screw
1 M6 nut

Standard FDM printing settings:
- Layer height: 0.2mm
- Infill: 70%
- Supports: As needed