Type Three Tuning Page -- Gasoline filler/Neck/Tank

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> > I'm hoping to repair my fuel tank sending unit. One of the copper
> > guides on the float has come un-soldered.

> That doesn't sound too difficult; they only short across the two wires
> really; you just need a bit of friction I guess so it doesn't jump about
> too much when the fuel slops.

The tiny hole in the side of the tube that contains the float is responsible for eliminating jumpyness; fuel just can't pass through that hole quickly enough to be annoying. The springs DO have to make good, continuous electrical contact, however. If contact is lost briefly the needle will twitch.
Tank over-flow
Everyone out there should take this to heart and, if your car is a 68-73, get familiar with your overflow hose. It is IMPORTANT to fix this. If you're not sure what I'm talking about, park your car with the steering turned all the way to the right. Reach up behind the RF tire and find the fuel filler tube (~2.5" dia.) Feel behind that tube until you find a rubber hose branching off of it and running inboard; this is your overflow hose.

Once you know where it is, you need to look at it. Get a flashlight and shine it on the rubber hose. If you see an obviously broken hose, or a hose that has lots of small cracks in it, then you probably need a new one.

There are 2 versions of these: 68-72 with 1/4 turn (bayonette) gas cap uses 311 201 179A which I have in stock. 72-73 with screw gas cap uses 311 201 179C which is NLA. The changeover was mid year 72.

If you want to verify that your hose needs to be replaced, go to the gas station and top up the tank. Then look up inside the fender. If you see gas running down the inside of the wheel well, then you need to fix it.

The gas that leaks out is not really the problem. Obviously you can fix that by just not filling the tank all the way up. The problem is that the RF tire throws dirt and water right up against there when you drive. An hour's drive in the rain can easily put a gallon of water in your tank through an overflow hose that still looks pretty good.

There is one more thing that you need to be aware of. These cars have a vent system for the gas tank. Its most common function is to let air in the tank to replace fuel as it is used. These vent systems are usually clogged up due to the steel lines that some of them used getting all rusted up inside. When the overflow hose is cracked, these cracks also serve as vents, so you never notice that there is a problem with the vent system, but when you fix the overflow hose, you now also need to at least check, and probably fix, the vent system.

Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA