BMW E30 Gas Tank, Fuel Lines, Filler Neck & Fuel Vapor Expansion Tank Installation Guide | 021

BMW E30 Gas Tank, Fuel Lines, Filler Neck & Fuel Vapor Expansion Tank Installation Guide | 021

In this BMW E30 project car episode, I finally get the fuel system refitted to the car including the gas tank, the fuel vapor expansion tank, and get all of the associated fuel lines hooked back up into the correct positions.

Here is that 12.7mm ID/20mm OD Fuel Hose: https://ebay.us/tZtt8M

Having done the underseal on the rear underside of the car, I'm very excited for the E30 build to enter its reassembly phase. At least for the rear end anyway!

The fuel tank I repaired a hole on and refinished in silver in a previous video is finally ready to be refitted.

Fuel BMW E30 fuel tank mounts up quite simply with 4 screws and one nut. I reused the old fasteners having refinished and plated them with zinc nickel.

Actually installing the fuel tank was quite easy, which is lucky as is had to drop it on at least 2 occasions in this video.

With that experience, I can confirm that when fitting the fuel system to a BMW E30, you must start by connecting up and fitting the fuel vapour expansion tank which lives above the filler neck in the wheel arch. The reason for this is that there is a line which routes through the body of the car and connects to the top of the fuel tank, and you will not be able to thread it through with the tank in place.

One of the common problems with an E30 fuel system is the petrol tank breather line, again this runs through the body of the car connecting between the top of the petrol tank itself and the fuel filler neck.

Once your fuel expansion bottle is refitted you can rehang the fuel filler neck and connect up that breather hose. Mine had ended up completely fossilised and rotten, so I replaced it with the hose linked above, cutting it down to 125cm in length.

The inner diameter of my replacement hose is 12.7mm which is just a little smaller than the original BMW item, but the closest I could source. With a bit of easing using a heat gun, this hose fits onto the connectors on both the fuel neck and gas tank side just fine.

With the fuel level sensor and fuel pump also plugged back in, all that's left to do is refit the arch liner and heat shields which protect the petrol tank from the heat of the exhaust.

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