Etienne Lau

I just refilled the DEF/Adblue fluid in my 2014 ML 350 bluetec. Previously I bought the 2.5gal/10L jugs from Autozone. The only downside I had was there was no good way of knowing when to stop filling without it overfilling other than listening to the fluid as it went down the fill tube.

However today I had the chance to use this item I recently purchased from IDParts: Adblue Fill Hose. It comes with an adapter to fit different jug openings for Adblue/DEF. One end of the tube screws onto the filler opening on the vehicle and the other end screws onto the jug itself. There is a smaller tube inside the larger tube. The smaller tube acts as the air burping tube and the larger tube allows the fluid to flow from the jug into the tank. There is a rubber ring that helps seal the connection with the jug, a spare rubber ring is included. As you pour the the DEF into the tank you'll start to hear the fluid gurgling as the air starts to enter the jug. The gurgling comes to a stop when the DEF tank is full and the fluid stops flowing.

Overall I am really happy with this product. Makes for a quick, simple and clean no leak solution to filling the DEF.

107123210

I bought similar large jugs from NAPA. They came with a flex hose. But no way of knowing when to stop pouring. However, I had bought a bottle of DEF some time ago from dealer to keep in car. Those bottles screw on and stop flowing when tank is filled. As many here have done, I cut the bottom off the dealer jug and used it as a funnel. Then poured from large container into the :funnel". It stops flowing when tank is full.

Etienne Lau

I am aware of this hack/technique. But still potential for messy spills as you that "funnel" that still contains fluid if the DEF tank becomes full. I used to have a VW Touareg TDI and Jetta TDI. Both DEF had tanks that filled in the spare tire well and this hack/technique would likely work well because the funnel sit nearly vertical. But the ML 350 Bluetec is filled from the rear side fender where you fill the fuel tank so the funnel would sit at an angle.

The other issue I can see with filling with the funnel is you must stop filling the funnel to allow it to drain into the DEF tank. This is not the case when using this hose as you just keep pouring until the DEF tank is full.

I also found the plastic hoses for the large DEF jugs from Autozone leak to some extent since they are "disposable", ie use once and throw away.

I guess to each their own as I can understand that some are content with the funnel hack/technique. I for one find this hose kit I bought to work well for me.