Bad leaky fuel cap advice wanted

Mr G Imp · Feb 10, 2019

I filled up the blue beauty today (1988 “turbo”) for the second time since I have owned it - on the way back I did a couple of stops and noticed the leak from cap all down the side of the rear wing and wheel arch!
It was doing this a bit before, but I did not realise how bad it was! as I went up a steep hill, the lights from the car behind showed the diesel literally spraying out! So I have parked her up and I’m looking for a new cap before I drive anywhere else.

So any recommendations? there are cheap ones on the bay but this looks ok.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/271590852296

mick 1986 · Feb 10, 2019

Mr G Imp said:
I filled up the blue beauty today (1988 “turbo”) for the second time since I have owned it - on the way back I did a couple of stops and noticed the leak from cap all down the side of the rear wing and wheel arch!
It was doing this a bit before, but I did not realise how bad it was! as I went up a steep hill, the lights from the car behind showed the diesel literally spraying out! So I have parked her up and I’m looking for a new cap before I drive anywhere else.

So any recommendations? there are cheap ones on the bay but this looks ok.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/271590852296

I fitted a britpart one to mine. I have had bad experiences with bearmach quality and won’t use them now. The cheap one was fine on mine though.

Flossie · Feb 11, 2019

It's not pressurising is it ?
TD can get a fault iirc with the pump that can cause back pressure or the vent is blocked?

Mr G Imp · Feb 11, 2019

Flossie said:
It's not pressurising is it ?
TD can get a fault iirc with the pump that can cause back pressure or the vent is blocked?

It seems ok regarding pressure - there is no hissing when the cap comes off - when it first happened I thought the fuel cap had fallen off there was such a stain on the wheel arch etc! I have ordered a new cap so will put that on and see

frog hopper · Feb 12, 2019

May be just the rubber washer damaged/missing. Is yours on the same key as the drivers door? be a pain to loose that, extra key to fumble for and all that.

mick 1986 · Feb 12, 2019

frog hopper said:
May be just the rubber washer damaged/missing. Is yours on the same key as the drivers door? be a pain to loose that, extra key to fumble for and all that.

I’m sure the older style cap can have the lock barrel swapped over.

dag019 · Feb 12, 2019

Might also be worth checking the filler neck itself. There are two different styles of filler cap (vented and non-vented) if the wrong one is fitted a vacuum will be created in the tank. To prevent this after fitting the wrong non-vented filler cap my ever resourceful previous owner had drilled a hole in the filler neck to act as a vent! I spent a long time swapping around new caps before inspecting the neck and discovering this.

If this is not the case and it is the cap that is leaking it is worth doubling up the seals. I had far more success with this than I did with bending the tabs to get a tighter seal against the neck. Having said this it still only lasts about 18 months before it will start leaking (seeping not pouring) on a full tank again and need the seals replacing.
Regardless of all the people who say it should not be a problem and they have never had it I believe, like many things, it is just an odd quirk of the defender. There are far too many defenders with the tell tale muddy triangle below the filler cap for it to not be a common problem. Whether it is from poor parts, or poor design, a regular replacement of the seals is the cure to prevent it happening.

Mr G Imp · Feb 12, 2019

frog hopper said:
May be just the rubber washer damaged/missing. Is yours on the same key as the drivers door? be a pain to loose that, extra key to fumble for and all that.

No...it’s on a different key - like the doors !

Mr G Imp · Feb 12, 2019

dag019 said:
Might also be worth checking the filler neck itself. There are two different styles of filler cap (vented and non-vented) if the wrong one is fitted a vacuum will be created in the tank. To prevent this after fitting the wrong non-vented filler cap my ever resourceful previous owner had drilled a hole in the filler neck to act as a vent! I spent a long time swapping around new caps before inspecting the neck and discovering this.

If this is not the case and it is the cap that is leaking it is worth doubling up the seals. I had far more success with this than I did with bending the tabs to get a tighter seal against the neck. Having said this it still only lasts about 18 months before it will start leaking (seeping not pouring) on a full tank again and need the seals replacing.
Regardless of all the people who say it should not be a problem and they have never had it I believe, like many things, it is just an odd quirk of the defender. There are far too many defenders with the tell tale muddy triangle below the filler cap for it to not be a common problem. Whether it is from poor parts, or poor design, a regular replacement of the seals is the cure to prevent it happening.

Pretty bad though as diesel spilled is slippery for motorbikes and the land rovers are bad enough on fuel as it is ! It shouldn’t really be a problem to be fair but there you go

Bad leaky fuel cap advice wanted

Mr G Imp

Active Member

mick 1986

Well-Known Member

Flossie

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Mr G Imp

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frog hopper

Well-Known Member

mick 1986

Well-Known Member

dag019

Well-Known Member

Mr G Imp

Active Member

Mr G Imp

Active Member

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