Fuel leak after filling to full

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GrahamFountain
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Fuel leak after filling to full

#1 Post by GrahamFountain »

I thought the fuel tank had gone on the doly, though it was only dripping slowly from under the boot. This was after I filled it right to the top for the first time in a while.
I had a look under the mat when I saw the drips, and I could see it was wet with fuel down the right hand side of the tank, but couldn't see any around the outlet itself. I didn't look at where the filler tube goes in, just started looking for a replacement tank.
But after a few days of use and about 1/4 tank gone, it's stopped leaking and the smell is gone.
So, assuming it's not the tank itself, what are the most likely places to look - when it stops raining again - and are there any bits worth ordering now to do the job this weekend or early next week?
It may be worth a mention that a painter replaced the rubber round where the filler comes through the rear wing. Don't think he had the tank out.
Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Carledo
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Re: Fuel leak after filling to full

#2 Post by Carledo »

Check the tank breather hose that reaches from the left rear corner of the tank up to near the top of the filler neck. It's almost certain to be old, cracked and original non ethanol resistant hose. Then have as much fun as I did getting 12mm R9 hose to replace it!

Also worth checking the seal round the tank sender unit.

Steve

PS, these days, I only ever fill to the first click off!
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
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Re: Fuel leak after filling to full

#3 Post by GrahamFountain »

Carledo wrote: Wed Jul 22, 2020 7:46 pm Check the tank breather hose that reaches from the left rear corner of the tank up to near the top of the filler neck. It's almost certain to be old, cracked and original non ethanol resistant hose. Then have as much fun as I did getting 12mm R9 hose to replace it!

Also worth checking the seal round the tank sender unit.

Steve

PS, these days, I only ever fill to the first click off!
Rimmers have that 141642 hose for about a tenner. Don't suppose anybody knows if that's ethanol resistant then. Mind you, I suppose it will last a few years, even if it's not.

How hard a job is it replacing that?

Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Carledo
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Re: Fuel leak after filling to full

#4 Post by Carledo »

GrahamFountain wrote: Wed Jul 22, 2020 8:02 pm
Carledo wrote: Wed Jul 22, 2020 7:46 pm Check the tank breather hose that reaches from the left rear corner of the tank up to near the top of the filler neck. It's almost certain to be old, cracked and original non ethanol resistant hose. Then have as much fun as I did getting 12mm R9 hose to replace it!

Also worth checking the seal round the tank sender unit.

Steve

PS, these days, I only ever fill to the first click off!
Rimmers have that 141642 hose for about a tenner. Don't suppose anybody knows if that's ethanol resistant then. Mind you, I suppose it will last a few years, even if it's not.

How hard a job is it replacing that?

Graham
I have no idea whether the Rimmers hose is ethanol resistant or not, my money would be on not! I got mine from the local factors after a bit of a song and dance. The original stuff didn't last long at all on the Carledo, but I teed into it for my EFi return, the lifespan was in weeks with ordinary supermarket fuel running constantly though the short length between the tee and the tank!

It's not hard to change, you need to remove the N/S boot millboard and the filler neck to get at the top fitting, but still only a few minutes work. You WILL need a good metre of hose!

Steve
Last edited by Carledo on Wed Jul 22, 2020 8:28 pm, edited 1 time in total.
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
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Re: Fuel leak after filling to full

#5 Post by GrahamFountain »

I'm also running supermarket (Tesco) Super. But I guess mine's only wet when the tank's full or sloshes around. I don't normally run over half full. But it's been cheap lately, and I succumbed to greed. Still I'll see what local factors have. Thanks.

Graham.
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
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Re: Fuel leak after filling to full

#6 Post by GrahamFountain »

would either 4.8 x 11.6mm or 5.6 x 12.6mm be right?

Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Carledo
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Re: Fuel leak after filling to full

#7 Post by Carledo »

I'm pretty sure the original is 1/2" bore, so the 12.6 would be spot on. I made do with 12mm cos it's what I could get!

Steve
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
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Re: Fuel leak after filling to full

#8 Post by GrahamFountain »

Ok. Thanks Steve, I'll get a meter. But optimist that I aren't, that'll make the problem something else.

Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Carledo
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Re: Fuel leak after filling to full

#9 Post by Carledo »

GrahamFountain wrote: Wed Jul 22, 2020 8:48 pm Ok. Thanks Steve, I'll get a meter. But optimist that I aren't, that'll make the problem something else.

Graham
If it was easy mate, anyone could and would be doing it. Where would the fun be in that?

Steve
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
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Re: Fuel leak after filling to full

#10 Post by GrahamFountain »

Having people who'll help helps.
Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Bish
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Re: Fuel leak after filling to full

#11 Post by Bish »

Don’t buy the rimmers pipe Graham! I did coz it was all I could find at the time. It took a serious effort with the hairdryer to warm it up enough to get it to fit. Quality looks like it will last five minutes or so :roll:
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Re: Fuel leak after filling to full

#12 Post by dollyman »

Just a thought, could the breather hose not be replaced with metal or copper pipe just joined by two small pieces of rubber pipe? Just thinking out loud :wink:

Tony.
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Re: Fuel leak after filling to full

#13 Post by GrahamFountain »

Bish wrote: Wed Jul 22, 2020 10:37 pm Don’t buy the rimmers pipe Graham! I did coz it was all I could find at the time. It took a serious effort with the hairdryer to warm it up enough to get it to fit. Quality looks like it will last five minutes or so :roll:
I try not to. And isn't it spelled "grimmers"?
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Carledo
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Location: Highley, Shropshire

Re: Fuel leak after filling to full

#14 Post by Carledo »

dollyman wrote: Thu Jul 23, 2020 10:26 am Just a thought, could the breather hose not be replaced with metal or copper pipe just joined by two small pieces of rubber pipe? Just thinking out loud :wink:

Tony.
Yes it's possible. But probably not a good idea for 2 reasons. 1) general unavailability of 12mm copper pipe (you can get it, but it's hard to find, expensive and almost impossible to bend, ask me how I know!) 2) the original lays against the wing and goes round and between bits of the roof support structure, you'd have to bracket it back or lag it to stop it rattling, it's too much like hard work when you can just put a bit of bendy rubber hose in and quietly forget it for a few years!

Steve
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
dollyman
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Re: Fuel leak after filling to full

#15 Post by dollyman »

Carledo wrote: Thu Jul 23, 2020 12:03 pm
dollyman wrote: Thu Jul 23, 2020 10:26 am Just a thought, could the breather hose not be replaced with metal or copper pipe just joined by two small pieces of rubber pipe? Just thinking out loud :wink:

Tony.
Yes it's possible. But probably not a good idea for 2 reasons. 1) general unavailability of 12mm copper pipe (you can get it, but it's hard to find, expensive and almost impossible to bend, ask me how I know!) 2) the original lays against the wing and goes round and between bits of the roof support structure, you'd have to bracket it back or lag it to stop it rattling, it's too much like hard work when you can just put a bit of bendy rubber hose in and quietly forget it for a few years!

Steve
Aah yes, i remember the route of it now Steve.

Tony.
NOW A CLUB MEMBER 2017057 :bluewave:
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