INSTALL: 25-Gallon Dually Wheel Well Water Tank for Sprinter

Last updated: October 12, 2026

How Do I Install the 25-Gallon Dually Wheel Well Water Tank (SP-DU-25) in a Sprinter?

Dually vans lose a lot of floor space to their extra-wide rear wheel wells. This guide covers mounting the GoCode Sprinter 25-Gallon Dually Wheel Well Tank into that space and setting up its ports, so you reclaim it for water storage instead of losing it to a bare wheel well.

Before You Start

  • Vehicle: Mercedes Sprinter

  • Kit: 25-Gallon Dually Wheel Well Water Tank - SP-DU-25

  • Mounting location: Over the dually rear wheel well (driver or passenger side)

  • Estimated installation time: ???

Tools & Materials

  • Drill or hole saw (roughly 1-3/4") to open the tank's pre-marked, capped ports

  • Support plate and mounting hardware (included with every order)

  • Insulation, if you want to fill the gap around the wheel well and prevent thermal bridging

  • A float-style level sensor, if you want a level gauge — GoCode recommends the KUS S5U-19 (sold separately)

  • What's included with tank: Support plate, mounting hardware

Installation Instructions

  1. Position the tank over the wheel well. It's shaped to sit over a dually's wheel well and can mount on either side — orient it end to end to match your build (for example, leaving room at one end for a water heater or other equipment).

  2. Keep it off the wheel well itself. Leave a gap between the tank and the wheel well so nothing touches — this avoids thermal bridging and leaves room to pack insulation in around the tank.

  3. Mount it with the support plate. Secure the tank using the support plate and mounting hardware included with every order.

  4. Open only the ports you need. Every port ships pre-marked and capped with a spin weld — drill or cut out only the ones you plan to use. The larger end has two 1.5" NPT ports and two 1/2" NPT ports; the end above the wheel well has one of each; the top has a single 1.5" NPT port.

  5. Drill out the top port for a level sensor, if you're installing one. A roughly 1-3/4" hole saw will open the top spin weld cleanly enough to thread in a float-style sensor.

  6. Plumb your fill, vent, and pickup lines. Use the 1.5" ports for fill and vent, and the 1/2" ports for your pickup and drain, depending on which end of your build they need to reach.

  7. Calibrate your level sensor to the tank's shape, if you install one. Because of the tank's asymmetric wheel-well profile, a float reading 50% doesn't mean the tank is actually half full — check the real volume at a few fill levels and calibrate your gauge or monitoring system accordingly.

Dually Wheel Well Tank Installation Video

Watch the install below, or follow the written steps above. Video by Fenix Off Grid Solutions.

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