Ducato Diesel Fuel Cap Leaking?

[Alshymer]

Hi
I am continually get a black oily mark around the fuel fill area and wonder whether the filler cap might be leaking.
Has anyone had this, found a method of repairing it or bought a replacement and managed to change the keys over?
Thanks

 

[Pudsey Bear]

Sounds like you're overfilling it, or going round right-handers on two wheels a lot.

 

[trevskoda]

Could be a rubber sealing ring worn or shrinking with the heat.
You should never fill a tank to the top and carry excess weight.

 

[wildebus]

Hi
I am continually get a black oily mark around the fuel fill area and wonder whether the filler cap might be leaking.
Has anyone had this, found a method of repairing it or bought a replacement and managed to change the keys over?
Thanks

Something that can certainly happen is if you fill up say in the morning and it is a hot day, you can get a bit of an pressure build up and fuel can leak out.
If it is all the time, have you checked the rubber seal on the cap has not been knocked askew a bit and so not sealing properly?

 

[Alshymer]

Could be a rubber sealing ring worn or shrinking with the heat.
You should never fill a tank to the top and carry excess weight.

Do you just fill until it cuts out or just anticipate what the tank will take?
Thanks for your replies.

 

[Wooie1958]

Fill it until the first click / cut off, that leaves enough room for expansion etc. etc.

 

[trevskoda]

Tank should have a self vent at top and cap should be tight and sealed.

 

[trevskoda]

Something that can certainly happen is if you fill up say in the morning and it is a hot day, you can get a bit of an pressure build up and fuel can leak out.
If it is all the time, have you checked the rubber seal on the cap has not been knocked askew a bit and so not sealing properly?

There will be a vent so no pressure build up in tank.

 

[Pudsey Bear]

Stop when it clicks, it clicks for a reason, this is why the diesel pump area is always slippy, which get's on your shoes, into the van/car and onto the brake pedal.

 

[wildebus]

There will be a vent so no pressure build up in tank.

You can still have this happen. I've had it a few times over the years on different vehicles.

 

[Wooie1958]

On our 2006 Peugeot Boxer based motorhome if i filled the tank ( first click ) then drove a decent distance say down to Canterbury when i got into Morrisons to refuel there was a loud hiss/rush of air as i removed the fuel cap, it did that from new until the day we sold it 18 years later.

 

[Pudsey Bear]

Ours always hisses if I let it get down to 1/4 full.

 

[trevskoda]

You can still have this happen. I've had it a few times over the years on different vehicles.

Yes me to but i looked for a blockage and sorted it, some tanks do have a releaf valve which holds a small pressure to insure a pressure feed to the injectors, some cars have it.

 

[colinm]

There is no 'open' vent on modern vehicles, most times when opening the filler I get a slight inrush of air, might have had pressure coming out but don't recall it happening.

 

[trevskoda]

There is no 'open' vent on modern vehicles, most times when opening the filler I get a slight inrush of air, might have had pressure coming out but don't recall it happening.

Ah well mine is old school and has a vent, dont like moderen cr-p.