Anti Gravity Valve and piping??

[freebie]

Hi All

New to this forum, and just purchased an 84 Rabbit diesel for my second car. Cars in decent shape but came with a bunch of problems. The timing is sorted out now, but when I got the car the fuel tank was crushed (from excessive vacumm in the tank??) I have replaced the tank but I noticed the fuel cap can be hard to remove after a bit of driving.
The repair manual shows the piping to and from the valve as ok? but the line going to the front of the car is just hanging in the engine compartment? should this not connect to the intake manifold?
Is it possible for a defective anti-gravity valve to allow that much negative pressure in the tank? or is there another problem I should be looking for.

BTW; This car was turbo, but now has a 1.6 N/A installed

Cheers

[Quantum TD]

The hose in the engine bay does not connect to anything. It should slip into a small hole on the top of the passenger side frame rail.

As for the tank: Hmm. That's strange. I've never seen/heard about that before. If I were you, I'd disconnect both fuel lines (feed and return) from the fuel filter, and try to blow air back to the tank. I'd do the same for that vent tube in the engine bay.

If all three are clear, then I'd drop the tank and check the gravity valve and the tubes that run along the filler tube.

[bottleworks]

As for the tank: Hmm. That's strange. I've never seen/heard about that before.

It happened on mine. I had to pull the tank and "re-inflate" it. When crushed in, it removed about 5 gals of volume. I ended up bypassing the valve...(I don't plan on flipping the car over). Make sure the vent line is not clogged before concluding that the valve is clogged.

[Fatmobile]

I put a filter on the end of the vent line on one of my cars,.. so bugs couldn't crawl into it and plug the vent line.
I've had one tank collapse.
I cut a V in the fuel cap seal to allow one car to vent.

Another problem that can be easily discovered by a vacuum gauge.

[freebie]

Thanks for all the replies;

I have checked the vent lines and they all seem to be clear, I have not gone through the service manual checkout on the gravity valve but if it can be eliminated? I would probably do that and install the filter on the end of the line in the engine compartment.

So this valve is required only when operating your Volkswagen upside down ??

[freebie]

The anti gravity valve?? has been removed and the tank pressure problem is gone! still not sure why the anti-gravity valve is installed? whats its purpose?

If you roll the rabbit, fuel stays in the tank??

Cheers

[Quantum TD]

If you roll the rabbit, fuel stays in the tank??

Pretty much.