Diesel Injector Return Hose End Plug

How to make your own in a pinch

The injector return hose end plug seems to be one of the more common places for fuel leaks on older diesel engines. In some cases I have seen it come completely off the injector, allowing fuel to pour down the back of the engine and onto the roadway.

Problem & Solution

Common among these chassis:


We sell injector end plugs separately and in some of our kits, but we often get asked how to make one in a emergency (like on the road away from home). You can do it with a cutting tool and a pair of pliers. This is another good argument on why to always carry a basic tool kit in the trunk of your car when you travel out of town - along with a little return hose in your emergency parts bag! 

In reality, the end plug is just a short piece of return hose with a small barbed metal plug shoved in the end. To make a replacement all you need is a 1 and 1/2 inch piece of hose and the metal plug from your original. Use a knife, wire cutter or razor to cut a slit in the hose and pry out the metal plug.

If you don't have any extra new hose with you, you might be able to borrow a little short piece from one of the existing hoses. If the hose is old and brittle you wont be able to use it. If possible take it from the long hose that runs from the No. 1 injector over to the factory fuel filter. If you have new hose it will be much better. Soak the short piece of hose in a little diesel fuel or dip in engine oil. This will help install the metal plug as well as slip it back onto the injector nipple. 

We sell injector hose in 1 meter lengths. I recommend you buy an extra meter and just leave it in the trunk of your Benz. Keep an eye on your engine and at the first sign of fuel wetness on or around the hoses replace them immediately. Your fuel economy and peace of mind with benefit!