Former VWDieselParts.com Forum

My plastic gas tank has a small leak mainly after fill ups. I was considering replacing my gas tank. Has anyone changed out their tanks and any tricks you can provide me with? Oh, by the way it is 1986 Golf Diesel.

If it's when filling up, have you checked to see if the leak is coming from the fill tube connection point or a vent/fuel line connection point? Changing a good tank to another good tank won't necessarily fix one of these issues.

If you do change the tank, yYou're in the south, so your straps may not be rusted too bad. If they are, buy new straps. I haven't pulled one out of a VW before, but you definately want the tank empty, or as empty as possible before you start. Fuel is approximately 8 lbs per gallon. It's a fairly easy task to do. Are you sure that there isn't a spot that you can fix the leak? If it's not on a seam, you should be able to buy epoxy and patch the hole.

I'd check the fuel sending unit, and the seal. I've seen quite a few sending unit rust on the tops of the feed/return tubes.

Or the vent tubes as noted.

The plastic tanks don't usually go bad.

Do I have to remove the tank to get to the sending unit or the sealing ring?

diesel freak wrote:Do I have to remove the tank to get to the sending unit or the sealing ring?

No. There is a round inspection cover in the trunk under the carpet. It's held in place with 3 phillips screws. Pull the cover off. You will see the 2 hoses (feed and return) and the wires for the sending unit. To get the unit out, you will unscrew (counterclockwise) the retaining ring around the outside of the sending unit. A big screwdriver or flat stock with a hammer against the ridges works well to get it out.

Before you pull the sending unit, look for wetness in that area. It should confirm that either the seal or the sending unit is bad.

You might want to have a vacuum cleaner handy,
seems like alot of crap gathers in the depression around the sender.

I found a fuel sender off an 87 Golf Gasser, can I use it in my Diesel?

Is yours leaking?

diesel freak wrote:I found a fuel sender off an 87 Golf Gasser, can I use it in my Diesel?

Yes and no. You will have to omit the red-yellow wires for the fuel pump. You'll also need to delete the internal fuel pump, and swap your pickup-tube off your diesel sending unit. Hard to explain, but you'll know what I'm talking about when you have them side-by-side.

I'd pull your diesel one and inspect for leaks. Then, go from there.

Anyone know where I can buy a fuel sender gasket? Tried all my local sellers with no avail.

Opened the hatch where the fuel sender is and discovered that the main threaded plastic top piece was not even hand tighten. The gasket around the fuel sender looked OK, even though it was flopping around and the whole well was encrusted with gunky diesel sludge and dirt. Back in 1987 I mistakenly filled my diesel up with gasoline, it ran for one block and I had it towed to the dealership. They charged me $50 to drain the tank. I wonder if they accessed the fuel sender to drain it and never put it back on properly. Hopefully I just fixed my leak and will no longer be looking for a gasket for the fuel sender.

It probably was that simple of a solution to stop the leak. You'll be the first to find out if it did stop it...........

Filled the tank up to see if it would leak. No more leaking but my fuel gauge not longer reads full only 3/4's. Is that my fuel sender freaking out since it no longer leaks past the top or is it my guage. It use to register full after a complete fill up.

diesel freak wrote:Filled the tank up to see if it would leak. No more leaking but my fuel gauge not longer reads full only 3/4's. Is that my fuel sender freaking out since it no longer leaks past the top or is it my guage. It use to register full after a complete fill up.

That's odd. I'd pull it out and check the contacts on the gradient-strip for the float. Not sure why that would be.