Club 80-90 Forums

OK, not the tank itself, but I'm assuming it's the sender seal. I replaced the tank just over a week ago, with all new grommets and breather pipes and a new sender seal. I even used a new genuine VW sender seal from Brickwerks, rather than the one supplied with the tank. When I filled up after fitting the new tank I was really pleased that nothing leaked. This evening I filled up for the second time, and when I got home I noticed a rapidly growing pool of petrol under the van.

It's not coming from the fuel outlet or the return pipe, or the filler grommet, or any of the three breather grommets, so it must be the sender seal. But the rate of the leak means it's not just a slightly ill-fitting seal (as though my Rustoleum paint finish wasn't perfect for instance) - it's as though it's failed completely. When I fitted the seal, since there isn't a recess for it in the top of the tank, I smeared a little Vaseline on it to hold it in place in the recess in the sender itself, and to ease the tightening of the sender - I figured if the seal was good against petrol it would be fine with a little petroleum jelly.

So what's happened? Has the mix of Vaseline and petrol inadvertently created a corrosive environment for the rubber seal? Has my Rustoleum paint around the sender hole dissolved in the petrol? Could the seal have split?

Whatever, I'm going to have to drop the tank again to investigate, but having just filled up in readiness for the Pikey meet this weekend it's going to have to wait till the tank's a bit emptier.

Lubing the seal is advisable but Rustoleum is not petrol resistant did you paint where the seal seats?

bigherb wrote:Lubing the seal is advisable but Rustoleum is not petrol resistant did you paint where the seal seats?

I did - I painted wherever there was undercoat. I guess that might be it then. When I take it apart again I'll strip the paint off where the seal sits, reassemble, and then paint Schutz up to where the seal sits. My old tank was a little rusty around the seal, and that may well have been where it leaked from, so I'd like to avoid that happening with the new tank.

Yesterday I dropped my fuel tank again to fix this leak. No prizes for spotting where the petrol was leaking.



The petrol has washed the underseal clean away, and it's lifted the Rustoleum off as well. It's brought the undercoat with it too, so effectively it's gone back to bare metal, exactly where I need the best protection from water pooling on top of the tank.





So I decided to go the whole way and strip the tank back to bare metal and repaint it - primer and acrylic rattle can job. I know the acrylic paint isn't petrol resistant either, but once the sender seal is taken care of that shouldn't matter - the petrol should stay on the inside. I left the ring around the sender seal unpainted, and used vaseline to make sure the sender seal was easy to fit and to act as a bit of waterproofing where there was bare metal.

The trouble is, I'm not convinced that's the end of it. The sender unit has a series of wedge shapes around the perimeter of the plastic body, and these are supposed to engage with the metal tabs around the hole in the tank, so that as the sender is rotated it pulls tighter onto the seal. Mine appears to have grooves cut by those metal tabs half way up the sender wedges, so it hasn't been pulling properly tight against the seal. So I did my best to reshape the wedges and to angle the tabs on the tank slightly so that they don't follow the grooves, but I've got a horrible feeling I'm going to need a new sender.

Something to look out for at Deva Dubs I guess. New ones are £55. Anybody know why Brickwerks list two versions - pre- and post-1986? The hole in the tank is identical in the early and late tanks. Do I need to be careful about which version I get when I'm trawling the second hand stalls?